C04 Att2 BCI-Final Report 2024.pdf

Conserving the world's bats and their ecosystems to ensure a healthy planet.

Final Report: Coronado National Forest

Abandoned Mine Bat Surveys January 22nd- 25th, February 5th - 9th 2024

Supplemental Project Agreement: 23-CS-11031600-337

The crew was greeted by a beautiful, early morning fog during the hike out to the last feature for the project.

BCI Photo by Corrie Harrison

Submitted April 02, 2024

Contents

Acknowledgements

Overview

Conservation Impact

Section 1: Survey Methods

Section 2: Survey Results

Contact

Appendix 1: Selected Photos

Appendix 2: Bat Habitat Assessments

Appendix 3: Closure Recommendations

Appendix 4: Exclusion Guidance

Acknowledgements

BCI wishes to thank Mark Schwab, Regional Abandoned Mines Program Lead, USFS Region 3, for initiating the project, providing the scope of work and site inventory descriptions, providing on-site navigation, and serving in the surface safety role during field work. Additional thanks to Abby Watson and Robin Bruno (Forest Geologists), and Bree Dean (NEPA Specialist) with the USFS, for joining the crew in the field.

All surveys were conducted by BCI Subterranean Team staff: Jackson Bain, Harrison Tamayo, Corrie

Harrison, Myriam Bishop, and Logan Miller. This report was authored by Corrie Harrison, with survey protocol content and report design by Shawn Thomas. Geospatial products were created by Priyesh

Patel.

Overview

BAT SURVEYS:

This biological survey project assessed abandoned mine land (AML) features in southern Arizona managed by the Nogales Ranger District, USFS. The AML features surveyed are located in the San Luis

Mountains, south of Arivaca, AZ. All sites were surveyed by Bat Conservation International (BCI) staff following standardized protocols and safety procedures for providing subterranean biological data and closure recommendations. Surveys focused on documenting bat and other wildlife use of each feature.

The field project resulted in bat surveys being conducted on 64 distinct features, comprising 72 openings to the surface (Table 1, Figures 1-3). Bat habitat assessments and closure recommendations are provided for all features. Selected photos appear in Appendix 1.

GUANO ANALYSIS:

Guano was collected from three features (CN-15, CN-18 and CN-65). Pooled guano samples are collected to determine species identification when bats are not present or cannot be confidently identified. Guano samples are preserved in RNA later and submitted to the Bat Ecology & Genetics Lab

(Species From Feces) at Northern Arizona University for DNA analysis to determine species composition. Detected species are listed in decreasing number of reads (highest to lowest proportion of sample).

Conservation Impact

BCI’s Subterranean Team works to protect subterranean bats and their habitat. Through our survey efforts, we assess subterranean features and identify sites that serve as critical habitat for bats and other wildlife, or as sources of water for wildlife. Bats are strongly associated with caves (and abandoned mines), and while not all bats use caves, a significant proportion of bat species are known to use caves during part of their life cycle (e.g., maternity roosting, hibernation, night roosting, fall swarming).

Subterranean bats serve as important contributors to nutrient-poor cave ecosystems by providing nutrients (through guano deposition) that may provide the foundation for complex biological communities of microbes, fungi, and invertebrates. Since all bats forage above ground, subterranean bats also serve critical roles in terrestrial ecosystems, where they contribute ecological services such as pollination and insect population control. Given the importance of subterranean bats to both surface and subsurface ecosystems, and because many bat species rely on caves and abandoned mines for survival, identification of subterranean habitat is necessary for implementing conservation. Our survey results directly inform recommendations for long-term protection of subterranean habitat.

The conservation impact of this project is the recommendation to protect 21 subterranean features, which collectively represent an estimated 10,400 ft2 of subterranean habitat.

Table 1. Summary of bat survey results and closure recommendations.

Feature1 Closure Rec.2 Live Bats3 Other Bat Sign Guano Analysis4 Roost Function Bat Habitat

CN-02 DCAT 0 none n/a none Poor

CN-03 LAI 0 none n/a n/a None

CN-04 LAI or DCAT 0 none n/a none Poor

CN-05 DCAT 0 none n/a none Poor

CN-06 DCWS 0 splatter, insect parts n/a day roost, night roost Marginal

CN-07 LAI or DCAT 0 none n/a none None

CN-08 LAI or DCAT 0 none n/a n/a None

CN-09 DCAT or LAI 0 none n/a none Poor

CN-10 LAI or DCAT 0 none n/a n/a None

CN-11 DCAT or LAI 0 none n/a none None

CN-12 LAI 0 none n/a none None

CN-13 LAI or DCWS 0 guano, insect parts n/a night roost Marginal

CN-13b LAI or DCWS

CN-14 LAI or BCAT 0 guano, insect parts n/a day roost, night roost Moderate

CN-15 BCAT 0

guano, insect parts, splatter, roost stain failed analysis day roost, night roost Good

CN-16 BCAT

1 CHME?

guano, insect parts, roost stain n/a day roost, night roost Moderate CN-16b BCAT

CN-16c BCAT

CN-17 DCWS

0 none n/a none Marginal

CN-17b DCWS

CN-18 BCCS 1 EPFU

guano, insect parts, roost stain

MACA & MYVE

night roost, warm season colony Excellent

CN-19 LAI or BCAT 0 guano, insect parts n/a day roost, night roost Moderate

CN-20 DCAT 0 none n/a none Poor

CN-22 BCAT 0 guano, insect parts n/a day roost, night roost Moderate

CN-23 LAI or DCAT 0 none n/a none None

CN-24 LAI or DCAT 0 none n/a none None

CN-25 LAI or DCAT 0 guano n/a day roost Marginal

CN-26 DCAT 0 none n/a none Poor

CN-27 DCAT 0 none n/a none Poor

CN-28 LAI 0 none n/a n/a None

CN-29 LAI or BCAT 0 guano, splatter, insect parts n/a day roost, night roost Good

CN-30 DCAT

0 none n/a none Poor

CN-30b DCAT

CN-31 LAI 0 none n/a none None

CN-32 DCAT 0 none n/a none Poor

CN-33 LAI 0 none n/a n/a None

CN-34 LAI 0 none n/a n/a None

CN-35 DCAT

0 none n/a none Poor

CN-36 DCAT

CN-37 DCWS 0 guano, insect parts n/a day roost, night roost Marginal

CN-38 LAI 0 none n/a none None

CN-39 BCAT 0 unknown n/a unknown Unknown

CN-40 DCAT 0 unknown n/a unknown Unknown

CN-41 LAI or OWC 0 guano, insect parts n/a night roost Marginal

CN-43 DCAT 0 none n/a none Poor

CN-44 DCAT 0 none n/a none Poor

CN-45 DCWS 0 none n/a none Marginal

CN-46 LAI or DCAT 0 guano n/a day roost Marginal

CN-47 DCAT 0 none n/a none Poor

CN-48 BCCS 1 COTO guano, insect parts n/a night roost, warm season colony Good

CN-49 LAI 0 none n/a none None

CN-50 LAI or DCAT 0 none n/a none Poor

CN-51 DCAT 0 none n/a none Poor

CN-52 LAI or BCAT 0 guano, insect parts n/a day roost, night roost Good

CN-53 LAI or DCAT 0 none n/a none Poor

CN-54 DCAT 0 none n/a none Poor

CN-55 LAI 0 none n/a n/a None

CN-56 BCAT 0 guano, insect parts n/a day roost, night roost Moderate

CN-57 DCAT 0 none n/a none Poor

CN-58 LAI or BCAT 0 guano, insect parts n/a day roost, night roost Moderate

CN-59 DCWS

0 none n/a none Marginal CN-59b DCWS

CN-59c DCWS

CN-59d DCWS

CN-60 BCAT 0 guano, insect parts n/a night roost Moderate

CN-61 DCWS 0 none n/a unknown Unknown

CN-62 LAI or DCWS 0 guano n/a day roost Marginal

CN-62b LAI or DCWS 0 guano, insect parts n/a night roost Marginal

CN-63 LAI 0 none n/a none None

CN-64 BCAT 0 guano, insect parts n/a night roost Marginal

CN-65 BCCS 0

guano, insect parts, roost stain

MYVE

night roost, warm season colony Excellent

CN-66 BCAT 0 guano, insect parts n/a night roost Moderate n/a – not applicable

1Feature: A distinct feature may consist of a single opening, multiple openings interconnected via underground workings, or closely related surface workings. In the “Feature” column, distinct features are separated by solid lines, and associated openings of a feature are separated by dashed lines. A feature contains shared biological and habitat characteristics and is therefore described by a single survey, whereas closure recommendations are unique to each opening.

2Closure recommendations: Wildlife-compatible Closures No Action

BCAT – bat-compatible closure, any time LAI – leave as is

BCCS – bat-compatible closure, cold season

BCWS – bat-compatible closure, warm season

OWC – other wildlife-compatible closure

Destructive Closures

DCAT – destructive closure, any time

DCWS – destructive closure, warm season

3Bat species codes: COTO – Townsend's big-eared bat (Corynorhinus townsendii)

EPFU – big brown bat (Eptesicus fuscus)

CHME – Mexican long-tongued bat (Choeronycteris mexicana)

MACA – California leaf-nosed bat (Macrotus californicus)

MYVE – Cave myotis (Myotis velifer)

4 Guano analysis: Pooled guano samples are collected to determine species identification when bats are not present or cannot be confidently identified. Guano samples are preserved in RNAlater and submitted to the Bat Ecology & Genetics

Lab (Species From Feces) at Northern Arizona University for DNA analysis to determine species composition.

Detected species are listed in decreasing number of reads (highest to lowest proportion of sample).

Figure 1: Overview Map of Project Area and Features Surveyed

Figure 2: North Area Map

Figure 3: South Area Map

Section 1: Survey Methods

BIOLOGICAL SURVEYS:

Biological data is collected via internal surveys after abandoned mine land (AML) features are assessed and determined to be safe to enter. Internal surveys are the most efficient and effective means of assessing habitat quality and wildlife use. Surveys are focused on subterranean habitat, with a primary emphasis on bat use. Surveys attempt to identify bat species present, document other bat sign (e.g., guano, insect parts, roost staining), and determine roost function of the site. Additionally, surveys document other wildlife use of features, evident by live animals, scat, nests, etc. All bat and other wildlife observations inform habitat assessments and closure recommendations.

BAT HABITAT ASSESSMENT SUMMARY:

Bat habitat assessments are determined based on observed bats and bat sign, along with physical characteristics of the site such as complexity and extensiveness of workings, portal size and obstructions, ceiling textures that bats select for, hydrological activity (such as seasonal flooding) that may preclude bat use, and any additional observations that may influence bat use of the site. A bat habitat assessment is applied to each distinct AML feature, which may include multiple openings.

• None

• Poor

• Marginal

• Moderate

• Good

• Excellent

• Unknown

See Appendix 2 for descriptions of bat habitat assessment classifications.

CLOSURE RECOMMENDATIONS:

Closure recommendations generally fall into bat-compatible or destructive closure categories and include a seasonal component that recommends the closure to occur either during the warm season, cold season, or at any time. A closure recommendation is provided for each individual opening of an AML feature and is selected from the following options:

• BCAT: Bat-compatible Closure, Any Time

• BCCS: Bat-compatible Closure, Cold Season

• BCWS: Bat-compatible Closure, Warm Season

• OWC: Other Wildlife-compatible Closure

• DCAT: Destructive Closure, Any Time

• DCWS: Destructive Closure, Warm Season

• LAI: Leave As Is

• CM: Closure Modification

• AC: Airflow Closure

See Appendix 3 for descriptions of closure recommendation classifications and Appendix 4 for guidance on conducting exclusion prior to closure.

Section 2: Survey Results

AML FEATURE DESCRIPTIONS:

Unless otherwise noted, all features are driven in moderate- to good-quality rock (qualitative safety assessment), contain good air*, and exhibit minimal signs of post-mining human disturbance. All feature locations are listed as latitude and longitude (decimal degrees) in the WGS84 datum.

* Good air is defined as no alarm sounding on the Altair 4x Multi-gas Detector carried during all surveys. The detector measures four gases (oxygen, carbon monoxide, hydrogen sulfide, methane) and alarms for gas levels that fall outside of safe thresholds.

Feature: CN-02

Location: 31.538835, -111.336744

Date: January 24, 2024

Observations: This feature is a shaft with a collar that is 6’Wx7’L and has an approximate depth of 10’.

The feature was completely flooded when the survey was conducted, so the true depth is unknown.

Bat Habitat: Poor

Closure Recommendation: Destructive Closure, Any Time (DCAT)

Feature: CN-03

Location: 31.539162, -111.334952

Date: January 24, 2024

Observations: This feature is a trench that is 8’Wx6’Hx14’L. The trench was filled with water when the survey was conducted. This feature provides no roosting habitat for bats and contains no dark zone.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

This feature presents no obvious hazards greater than those inherent to the landscape. The trench holds water during certain times of the year and LAI would enable wildlife to continue to utilize the site as a water source.

Feature: CN-04

Location: 31.537462, -111.337520

Date: January 25, 2024

Observations: This feature is a shallow shaft that is 7’Wx10’L and is 9’ deep. This feature contains no subterranean habitat and no dark zone.

Bat Habitat: Poor

Closure Recommendation: Leave As Is (LAI)

Alternative Closure Recommendation: Destructive Closure, Any Time (DCAT)

Feature: CN-05

Location: 31.545715, -111.336866

Date: January 24, 2024

Observations: This feature is a well that is 4’Wx4’L and goes down 19’. It has a 6’ long culvert for the collar that is set into cement for support. Below the culvert, the rest of the well wall is solid rock and contains water at the bottom. The subterranean workings are minimal. A snake shed was seen where the culvert intersects the bedrock layer. This feature creates a pitfall hazard for people as well as wildlife.

Feature: CN-06

Location: 31.539068, -111.335317

Date: January 24, 2024

Observations: This feature is an adit that has a 4’Wx6’H portal opening and is 28’ long, ending in solid rock. Historical items included a single piece of timber. Bat sign documented was splatter on the wall and moth wings. This feature is used very lightly as a day and a night roost. The adit contains a very limited dark zone. Other wildlife seen was woodrat scat and midden.

Bat Habitat: Marginal

Closure Recommendation: Destructive Closure, Warm Season (DCWS)

Follow exclusion protocols in BCI’s “Managing Abandoned Mines for Bats.” See Appendix 4.

Feature: CN-07

Location: 31.53943050, -111.33641859

Date: January 24, 2024

Observations: This feature is a shallow shaft that has a 5’Wx10’L collar and was flooded during the time of the survey

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

This feature retains water, and LAI would allow wildlife to continue to utilize the feature as a guzzler.

Alternative Recommendation: Destructive Closure, Any Time (DCAT)

Feature: CN-08

Location: 31.540582, -111.335112

Date: January 24, 2024

Observations: This feature is a prospect cut on a hillside. A small trench leads to a 6’ high wall. This feature contains no subterranean habitat.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

This feature presents no obvious hazards greater than those inherent to the landscape.

Feature: CN-09

Location: 31.539875, -111.336083

Date: February 7, 2024

Observations: This feature has a 60’ long trench that varies from 6’-20’ deep, leading to an 8’ long adit.

Bat Habitat: Poor

Alternative Closure Recommendation: Leave As Is (LAI)

Feature: CN-10

Location: 31.539845, -111.339655

Date: February 8, 2024

Observations: This feature is a 7’Wx10’Hx25’L trench and contains no subterranean workings.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious hazards greater than those inherent to the landscape. Fencing and signage could be added to minimize safety concerns.

Feature: CN-11

Location: 31.539534, -111.338754

Date: January 24, 2024

Observations: This feature is a shaft with a 6’Wx5’L collar. The shaft is completely flooded up to the last 3’ from the surface and contains no subterranean workings. The water is at least 16’ deep.

Bat Habitat: None

Alternative Closure Recommendation: Leave As Is (LAI)

Feature: CN-12

Location: 31.540894, -111.339677

Date: January 24, 2024

Observations: This feature has self-remediated and contains no subterranean workings.

Bat Habitat: None

Feature: CN-13 / CN-13b

Location: 31.539660, -111.341617

Date: January 24, 2024

Observations: This feature is a trench that is 4’Wx20’Hx60’L and is subdivided by a 20’L tunnel. The face of the trench ends in collapse. The tunnel feature contained four guano pellets and a pair of moth wings indicating a minor night roost. Other wildlife sign included woodrat scat.

Bat Habitat: Marginal

Closure Recommendation:

CN-13: Leave As Is (LAI)

CN-13b: Leave As Is (LAI)

Alternative Closure Recommendation:

CN-13: Destructive Closure, Warm Season (DCWS)

CN-13b: Destructive Closure, Warm Season (DCWS)

Feature: CN-14

Location: 31.539997, -111.341217

Date: February 8, 2024

Observations: This feature is an adit with a 6’Wx10’H portal opening that quickly narrows down to a

4’Wx2’H constriction, then opens into standing height. The adit is driven into solid rock and has 235’ of horizontal workings before ending in collapse. This feature also contains two stopes, located towards the portal and the face of the mine, that extend upwards and are 33’ and 12’ in length, respectively. Nails, drill holes, and a few 8’ long pieces of lumber were seen throughout the feature. Scattered guano, beetle/cricket parts, and moth wings were primarily found within the first 100’ of the adit. Guano was also seen at the face of the mine near the collapse. Insect parts and light guano scatter indicate feature is utilized as a night and a day roost. Other wildlife signs observed were javelina remains, lots of javelina scat, small carnivore scat, woodrat scat, and ringtail scat. Live wildlife in mine includes spiders and flies.

Bat Habitat: Moderate

Closure Recommendation: Leave As Is (LAI)

This feature presents no obvious structural concerns or internal physical hazards. LAI would provide the least impact to wildlife utilizing this feature and preserve habitat for larger wildlife that would otherwise be excluded by standard bat gates. Maintenance on current fencing and signage could help to minimize safety concerns.

Alternative Closure Recommendation: Bat-compatible Closure, Any Time (BCAT)

A removable bar and a gate with 6” bar spacing is recommended for this feature.

Feature: CN-15

Location: 31.540103, -111.341870

Date: January 24, 2024

Observations: This feature has a 50’ long trench that leads to an adit with a 4’Wx6’H portal opening and extends back 112’. There was standing water ranging from 6” – 2’ deep that was present throughout the feature. Bat sign includes light scatter, splatter, moth wings, beetle/cricket parts, and roost staining.

This indicates the feature is utilized as a night roost and a day roost. Guano and splatter were observed on the ribs and the back of the mine. Insect parts were seen floating in the water. Bat use is likely more significant than what was observed, but the flooded adit could be preventing sign building up from year to year.

Bat Habitat: Good

Guano Analysis: A guano sample collected for species identification was preserved in RNA later and submitted to the Bat Ecology & Genetics Lab at Northern Arizona University for DNA analysis to determine species composition. For indeterminate reasons, the Lab was unable to sequence the guano sampled at this site.

Closure Recommendation: Bat-compatible Closure, Any Time (BCAT)

Feature: CN-16 / CN-16b / CN-16c

Location: 31.54070643, -111.34016247 (CN-16)

31.54051735, -111.3404471 (CN-16b)

31.5406963, -111.3401064 (CN-16c)

Date: January 24, 2024

Observations: This feature is a singular stope approximately 6’Wx40’Hx100’L and is accessed by three openings. CN-16b is an adit that is located at the southwestern end of the feature and serves as the most accessible entrance. This portal entrance is situated in a trench and accesses the upper portion of the feature. The adit continues to the main stope, which then opens to the surface by CN-16. Past the main stope on the same trajectory is the shaft feature CN-16c. The bottom of the shaft was not accessible to survey and contained three unsurveyed drifts. Historical stulls, timbers, wire, rusty containers, and modern trash were observed throughout the feature. Bat sign includes light guano scatter, moth wings, beetle/cricket parts, and roost staining. A live bat was observed but could not be positively identified; it was suspected to be a Mexican long-tongued bat (Choeronycteris mexicana). Other wildlife sign includes an owl nest and guano, dead jackrabbit, snake shed, and mesocarnivore and large carnivore scat.

Bat Habitat: Moderate

Closure Recommendation:

CN-16: Bat-compatible Closure, Any Time (BCAT)

CN-16b: Bat-compatible Closure, Any Time (BCAT)

CN-16c: Bat-compatible Closure, Any Time (BCAT)

A bat gate with 6” bar spacing is recommended for all entrances. For portal CN-16b, a removable bar is recommended to allow for future access.

Feature: CN-17 / CN 17b

Location: 31.539782, -111.341487 (CN-17)

31.53990471, -111.3414021 (CN-17b)

Date: January 24, 2024

Observations: This feature is a shaft that has a 4’Wx23’L collar and descends 26’ where it intersects a horizontal crosscut. One drift extends to the southwest and is 63’ in length. The other drift extends to the northeast 33’ to CN-17b entrance, which is too small to enter. The feature is flooded up to 3’ deep, except for a small landing where the shaft enters the crosscut. No bat sign was seen but it should be noted that the water could obscure/degrade any guano or insect parts. Other wildlife sign noted was woodrat scat and cocoons.

Bat Habitat: Marginal

Closure Recommendation:

CN-17: Destructive Closure, Warm Season (DCWS)

CN-17b: Destructive Closure, Warm Season (DCWS)

Feature: CN-18

Location: 31.53965291, -111.34029851

Date: February 8, 2024

Observations: This feature is an adit with a 5’Wx8’H portal and extends back 222’, ending in solid rock. 70’ from the portal is a 5’Hx5’L underhand stope. Both modern human disturbance and cultural artifacts were found within this mine. Modern disturbance included plastic bottles, a shoe, food packages, and an aluminum mineral survey tag. Cultural artifacts seen included miner graffiti, plywood, rusty food cans, and glass shards. Lots of bat sign was seen throughout the feature. This included heavy scatter of guano, piles of guano (some a few inches tall), insect parts, roost staining, and one live big brown bat (Eptesicus fuscus). This bat sign, along with temperatures ranging from 72°F-77°F, indicates this feature is utilized by a warm season colony. Insect parts, which included moth wings and beetle/cricket parts, also points towards this feature being used as a night roost.

Bat Habitat: Excellent

Guano Analysis: A guano sample collected for species identification was preserved in RNA later and submitted to the Bat Ecology & Genetics Lab at Northern Arizona University for DNA analysis to determine species composition. The guano sampled identified two species to be present at this site:

California leaf-nosed bat (MACA) and cave myotis (MYVE).

Closure Recommendation: Bat-compatible Closure, Cold Season (BCCS)

Feature: CN-19

Location: 31.540200, -111.341012

Date: February 8, 2024

Observations: This feature is an adit with a portal opening 8’Wx3’H and extends back 17’, ending in solid rock. Bat sign was comprised of light and heavy guano scatter, moth wings, and beetle/cricket parts. This sign indicates the feature is used as a day and a night roost. Other wildlife sign includes bird feathers, eggshells, woodrat scat, and small mammal scat.

Bat Habitat: Moderate

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious structural concerns or internal physical hazards.

LAI would provide the least impact to wildlife using this feature. Fencing and signage could be added to minimize safety concerns.

Feature: CN-20

Location: 31.543965, -111.345862

Date: January 24, 2024

Observations: This feature is a shaft with a 7’Wx9’L collar and has an approximate depth of 13’. There is no dark zone, and the shaft is flooded 9’ from the surface.

Feature: CN-22

Location: 31.544803, -111.342910

Date: February 8, 2024

Observations: This feature is an adit with a 3’Wx3’H portal opening. Right after the entrance, the adit slopes down for 6’ at a 20° angle and then levels off. The feature continues for 58’ and ends in solid rock. Most of the feature contains 2’ of standing water. Very light guano scatter was seen throughout the feature, with one concentrated area of heavy scatter at the face of the mine. A few moth wings were located near the heavy guano scatter, and beetle parts were seen sparsely throughout the feature. This sign indicates the feature is utilized as a day and a night roost. Other wildlife sign included mud wasp nests, woodrat scat and nest, and small mammal scat.

Bat Habitat: Moderate

Closure Recommendation: Bat-compatible Closure, Any Time (BCAT)

A culvert closure is recommended to prevent rock debris from further constricting the portal entrance. A removable bar and a gate with 6” bar spacing is also recommended for this feature.

Feature: CN-23

Location: 31.543283, -111.344233

Date: January 24, 2024

Observations: This feature is a shaft with a 19’Lx7’W collar and is 8’ deep. The shaft was completely flooded to the surface and had a thin layer of duckweed across the top.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

This feature is a half mile from any publicly accessible roads and is stable with little risk of collapse.

LAI would preserve this feature as a water source for animals.

Feature: CN-24

Location: 31.543312, -111.344150

Date: January 24, 2024

Observations: This feature is a prospect shaft with a 6’Wx9’L collar and is 6’ deep. The feature is completely flooded and has a small amount of duckweed on the surface.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

This feature is a half mile from any publicly accessible roads and is stable with little risk of collapse.

Feature: CN-25

Location: 31.542033, -111.342761

Date: February 8, 2024

Observations: This feature is an adit with a 4’Wx6’H portal opening. It extends 35’ before ending in solid rock. This feature contained standing water that was 2’ deep. Bat sign consists of light guano scatter which indicates the feature is primarily used as a day roost. Other wildlife sign includes javelina scat, woodrat scat, and a paper wasp nest.

Bat Habitat: Marginal

Closure Recommendation: Leave As Is (LAI)

This feature is a half mile from any publicly accessible roads and is stable with little risk of collapse.

Feature: CN-26

Location: 31.538861, -111.350095

Date: January 25, 2024

Observations: This feature is a shaft with a 9’Wx8’L collar and is 11’ deep. The shaft contains no dark zone.

Feature: CN-27

Location: 31.536827, -111.349837

Date: January 25, 2024

Observations: This feature is a shaft with a 7’Wx9’L collar and extends 25’ down where it becomes flooded with water. Water is an unknown depth. This shaft contains no dark zone.

Feature: CN-28

Location: 31.536946, -111.346758

Date: January 25, 2024

Observations: This feature has been naturally remediated; there is no portal opening and no subterranean workings.

Bat Habitat: None

Closure Recommendation: Leave As Is

This feature has self-remediated and needs no further work.

Feature: CN-29

Location: 31.538046, -111.349320

Date: January 25, 2024

Observations: This feature is an adit with a 3’Wx3’H portal entrance that opens into standing height once inside. The adit is driven back 94’ into solid rock. Cultural sign seen within feature includes an aluminum metal tag with flagging. Bat sign documented was splatter, light guano scatter, moth wings, and beetle/cricket parts. These items indicate that the feature is utilized as a day and a night roost. The guano varied in size, which points towards the roost being used by multiple species. Other mammal sign noted was lots of javelina scat, a large mammal spine, medium mammal scat, spider webs, woodrat scat, and a mouse nest.

Bat Habitat: Good

Closure Recommendation: Leave As Is (LAI)

This feature presents no obvious structural concerns or internal physical hazards. LAI would provide the least impact to wildlife using this feature and preserve habitat for larger wildlife that would otherwise be excluded by standard bat gates. Fencing and signage could be added to minimize safety concerns.

Feature: CN-30 / CN-30b

Location: 31.532696, -111.340936 (CN-30)

31.53284773, -111.3408595 (CN-30b)

Date: January 25, 2024

Observations: This feature is a collapsed shaft that is divided by a narrow 1’W archway, forming two collars. CN-30 collar is 8’Wx10’L and extends down 14’. The shaft contains no dark zone and holds water at the bottom. A cable and a few timbers were seen within the shaft. The archway could be utilized by bats as a night roost, but no bat sign was found underneath it. Other wildlife sign documented was woodrat scat, dead insects, and a spider egg case.

Bat Habitat: Poor

Closure Recommendation:

CN-30: Destructive Closure, Any Time (DCAT)

CN-30b: Destructive Closure, Any Time (DCAT)

Feature: CN-31

Location: 31.533783, -111.340400

Date: February 7, 2024

Observations: This feature has a 10’Wx15’Lx5’H trench that leads to a completely collapsed adit. Lots of loose, clay-like material comprises the majority of the collapse, along with some small rocks and tree roots. A small, wooden sign that says, “keep out” and a glass jar were found within the trench. There are no accessible subterranean workings at this site.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

The adit has self-remediated, and the trench feature poses no danger that is not already inherent on the landscape.

Feature: CN-32

Location: 31.533078, -111.339959

Date: January 25, 2024

Observations: This feature is a shaft that has a 4’Wx25’L collar and has an unknown depth due to the shaft being flooded at the time of the survey. A few pieces of lumber was documented around the collar, and a deer skeleton was seen floating on the surface of the water.

Feature: CN-33

Location: 31.530819, -111.340519

Date: January 25, 2024

Observations: This site contains a series of collapsed workings that extend straight uphill for about

100’. There is no subterranean habitat present. Various scattered timbers and lumber were seen.

Feature: CN-34

Location: 31.534885, -111.342805

Date: January 25, 2024

Observations: This feature is a 20’Wx30’Lx6’H prospect pit. The prospect pit contained standing water about 2’ deep. Floating timbers and vegetation were seen submerged in the water.

Feature: CN-35 / CN-36

Location: 31.533620, -111.345773 (CN-35)

31.533681, -111.345972 (CN-36)

Date: February 7, 2024

Observations: This is a trench feature that is 3’W, ranges from 4-8’H and is 75’L. Halfway through the trench is a 10’L land bridge connecting CN-35 to CN-36. Cultural items seen at the site were nails, an aluminum metal tag, a rusty can, and a Styrofoam cup. Other wildlife sign was a mud wasp nest.

Bat Habitat: Poor

Closure Recommendation:

CN-35: Destructive Closure, Any Time (DCAT)

CN-36: Destructive Closure, Any Time (DCAT)

Feature: CN-37

Location: 31.534860, -111.342611

Date: February 7, 2024

Observations: This feature is an adit with a small 3’Wx2’H portal opening. The adit declines down 8’ at 30° and then hits a pool of water 1’ deep and 7’ in length. The adit then continues up at a slight incline and ends in solid rock. Cultural items seen were an aluminum metal tag and a screwdriver. Bat sign documented was moth wings and a few guano pieces on wall. The bat sign was not very significant, and the feature is probably lightly used as a night and a day roost.

Bat Habitat: Marginal

Feature: CN-38

Location: 31.534578, -111.342357

Date: February 7, 2024

Observations: This feature has completely collapsed, and the original entrance could not be found.

Bat Habitat: None

Feature has self-remediated and needs no further work.

Feature: CN-39

Location: 31.535300, -111.343667

Date: February 7, 2024

Observations: This feature is an adit that has a 5’Wx3’H portal opening and is greater than 100’ in length. The feature is driven downhill, following the ore body with stopes on either side. After 60’ from the portal, a drift branches sharply to the left, towards a possible collapsed entrance. The main drift continues, and there could be a possible additional drift to the right. While conducting the survey, a noise (similar to a rock falling) was heard from the drift to the left. The surveyor came back out to the entrance after hearing the noise, and the rest of the survey was subsequently called off due to safety. A couple of historical items were seen within the area that was surveyed, including an aluminum mineral survey tag and some corrugated metal. This adit sees significant human use from people migrating through the area. The floor near the entrance and 60’ back was completely covered in various items that included large black bags, jugs, bottles, clothing, food packaging, canned food, camouflage backpacks, and blankets. No bat sign was observed within the section of the mine that was surveyed, but the amount of trash on the floor could easily obscure any sign that was present. Other wildlife sign documented include a dead skunk, skunk scat, a snake skeleton, and woodrat scat. The mine also smelled heavily of a skunk.

Bat Habitat: Unknown

Closure Recommendation: Bat-compatible Closure, Any Time (BCAT)

A bat gate with 6” spacing and a removable bar is recommended to allow for future entry/monitoring at this feature. Since this site sees significant human use, placing the gate further back into the feature is also recommended in order to provide enough shade and shelter from the elements.

Feature: CN-40

Location: 31.535533, -111.343900

Date: February 7, 2024

Observations: This feature has a 5’Wx5’L portal opening and was completely flooded at the time of the survey.

Bat Habitat: Unknown

Feature: CN-41

Location: 31.522126, -111.341083

Date: February 7, 2024

Observations: This feature is an adit that has a 4’Wx3’H portal opening. Past the portal opening 20’, there is a 10’ stope on the left and a 20’ drift to the right (which circles back to the main adit). Off the

20’ drift is a 2’Wx2’Hx10’L stope. The feature continued to be driven down at a 35° angle for 90’ before leveling out to even ground. The adit continues another 20’ before constricting down to a

2’Wx1’H squeeze. Just past the squeeze the adit opens to standing height and continues another 20’ before ending in solid rock. The feature gets very warm (71°F) and humid (73 RH) closer to the face of the mine. Historical sign seen were lumbers, nails, a metal hook on the ribs of the mine, wooden steps, two food cans, an old metal pipe, and some metal railing sticking out from adjacent collapsed portal.

The only modern human disturbance documented was an older Budweiser can at the face of the mine.

Bat sign was very sparse and was only found within 30’ of portal. It consisted of a few pieces of guano and moth wings, indicating the feature is used as a night roost. Other wildlife sign includes a live gray fox observed from the portal, fox scat, javelina scat and skull, small mammal bones, and spider webs.

Bat Habitat: Marginal

Closure Recommendation: Leave As Is (LAI)

LAI would provide the least impact to wildlife using this feature and preserve habitat for larger wildlife that would otherwise be excluded by standard bat gates or destructive closure. Fencing and signage could be added to minimize safety concerns.

Alternative Closure Recommendation: Other Wildlife-compatible Closure (OWC)

A small “mammal door” is recommended to allow continued access for gray foxes to use this feature as a den. Closure should occur outside their denning period, between July-December. A gate with a removable bar and 6” bar spacing is recommended for this feature.

Feature: CN-43

Location: 31.535598, -111.312435

Date: February 7, 2024

Observations: This feature is a short, 6’L prospect with a 5’Wx5’H portal opening. It contains about 4” of seasonal standing water. This feature contains no true dark zone. No bat sign was seen during the survey. Other wildlife sign includes woodrat scat, remnants of bird nest, and spider webs.

Feature: CN-44

Location: 31.510072, -111.324098

Date: January 25, 2024

Observations: This feature is a shaft with an 8’Wx10’L collar and has an unknown depth. The shaft is flooded about 6’ from the surface. It contains no subterranean workings and has no dark zone.

Feature: CN-45

Location: 31.508752, -111.325983

Date: January 25, 2024

Observations: This feature is a collapsed shaft with a 15’Wx25’L collar and is 15’ deep. The collapse makes it possible to walk into the feature without any rigging. It contains a lateral drift at the base that is

18’ long and ends in solid rock. At the end of the drift is a pool of water about 2’ deep. No bat sign was seen; however, seasonal flooding could obscure any sign from building up. Other wildlife sign includes woodrat scat, mouse scat and a nest.

Bat Habitat: Marginal

Feature: CN-46

Location: 31.505861, -111.344234

Date: February 7, 2024

Observations: This feature is an adit that has a 5’Wx5’H portal opening and extends back 16’, ending in solid rock. Historical sign seen includes rusty cans, small timbers, and two nails on ribs. Modern human disturbance included trash bags, empty bottles, cans, jugs, and a USB charger battery pack. The only bat sign seen was light guano scatter, indicating that this feature is utilized as a minor day roost.

The adit contains only a twilight zone and never gets fully dark. Other mammal sign seen was woodrat and small mammal scat.

Bat Habitat: Marginal

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious structural concerns or internal physical hazards.

Signage could be added to minimize safety concerns.

Alternative Closure Recommendation: Destructive Closure, Any Time (DCAT)

If a destructive closure is the chosen closure method, it’s worth noting that this feature is adjacent to two other significant shaft features (>50’ deep) that have never received a biological survey. If future surveys are conducted on the other shafts, all features could be closed at the same time (if needed).

Feature: CN-47

Location: 31.505313, -111.322097

Date: January 23, 2024

Observations: This feature is a shaft with a 6’Wx8’L collar and is 13’ in depth. The bottom of the shaft is sumped, with a lateral drift that extends 10’ and ends in solid rock. The only historical items noted were timbers. No bat sign was seen, and the feature contains a limited dark zone. The only other wildlife seen was woodrat scat.

Feature: CN-48

Location: 31.504272, -111.327495

Date: February 8, 2024

Observations: This feature has a 20’L trench that leads to a 10’L archway. Just past the archway is an adit with a 7’Wx8’H portal opening. At the portal opening is a 5’Wx’5Lx8’H underhand stope. The feature continues past the stope for another 65’, ending in solid rock. Historical items seen were black plastic piping and pieces of lumber and timber. A live Townsend’s big-eared bat was seen hibernating underneath the archway. Other bat sign seen was heavy guano scatter, moth wings, and beetle/cricket parts. Heavy guano scatter indicates warm season use, while the insect parts show that this feature is also utilized as a night roost.

Bat Habitat: Good

Closure Recommendation: Bat-compatible Closure, Cold Season (BCCS)

A bat gate with 6” bar spacing is recommended for this feature as well as a visual inspection underneath trench feature to make sure there are no hibernating bats.

Feature: CN-49

Location: 31.505335, -111.321819

Date: January 23, 2024

Observations: This feature is a prospect trench that is 4’Wx5’Hx20’L. The end of the trench contains an adit that extends back 2’. This feature contains no subterranean habitat.

Feature: CN-50

Location: 31.503307, -111.329880

Date: February 8, 2024

Observations: This feature is a short 4’Wx2’Hx5’L prospect adit that has been flooded. Water could be obscuring a small portal opening. The feature contains no subterranean workings and no dark zone.

Historical items seen outside of the feature include a shovel head. Modern human items documented were camouflage gear, plastic bottles, and food packaging.

Bat Habitat: Poor

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious structural concerns or internal physical hazards.

Signage could be added to minimize safety concerns.

Feature: CN-51

Location: 31.492550, -111.309238

Date: January 23, 2024

Observations: This feature is a shallow shaft with a 9’Wx13’L collar and extends down 10’. The bottom of the shaft is filled with 3’ of water. This feature contains no subterranean workings or dark zone.

Feature: CN-52

Location: 31.479615, -111.285508

Date: February 6, 2024

Observations: This feature is an adit with a 3’Wx5’H portal opening. The adit extends back 15’ and ends in solid rock. Bat sign seen includes heavy guano scatter, moth wings, and beetle/cricket parts. This sign indicates that the feature is utilized as a night and a day roost. Woodrat scat was also seen outside of the feature.

Bat Habitat: Good

Closure Recommendation: Leave As Is (LAI)

This feature presents no obvious structural concerns or internal physical hazards. LAI would provide the least impact to wildlife using this feature and preserve habitat for larger wildlife that would otherwise be excluded by a bat gate.

Feature: CN-53

Location: 31.483852, -111.310470

Date: February 8, 2024

Observations: This feature is an adit with a 5’Wx5’H portal opening and extends back 10’, ending in solid rock. A lot of human trash was seen within the feature. This included trash bags, food containers, food packaging, a Camelbak pack, a backpack, plastic bottles, clothing, and bailing twine. Wildlife sign seen was bird guano, woodrat scat, a mud wasp nest, and some kind of chrysalis.

Bat Habitat: Poor

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious structural concerns or internal physical hazards.

Feature: CN-54

Location: 31.490534, -111.307046

Date: January 23, 2024

Observations: This feature is an adit with a 4’Wx6’H portal opening and extends back 22’. The face of the adit contains a pool of water. This feature declines at a moderate grade and dimensions narrow as it descends. The only wildlife sign seen was bird feathers.

Feature: CN-55

Location: 31.488253, -111.304884

Date: February 8, 2024

Observations: This feature is a prospect pit that is 15’Wx3’Hx10’L. The pit was filled with water at the time of the survey.

Bat Habitat: None

Closure Recommendation: Leave As Is (LAI)

LAI would help to preserve water retention on the landscape, and wildlife could continue to utilize the feature as a water source.

Feature: CN-56

Location: 31.491788, -111.308736

Date: January 23, 2024

Observations: This feature is a shaft with a 5’Wx8’L collar opening and is 54’ deep with water at the bottom. The shaft is driven down at a 75°-85° angle. A 13’ lateral drift extends off the main shaft 40’ from the collar. A second, 17’ lateral drift also extends off the shaft. Both drifts end in solid rock.

Historical sign documented were timbers and a ladder. Bat sign includes light guano scatter, beetle/cricket parts, and moth wings, indicating this feature is used as a night and a day roost. The 17’ lateral drift contained the area where the bat sign was located. Other wildlife sign seen included an owl pellet, bird guano, a rodent skull, spiders, and spider webs.

Bat Habitat: Moderate

Feature: CN-57

Location: 31.468028, -111.268292

Date: January 23, 2024

Observations: This feature is a prospect shaft that is 6’Wx10’Lx8’H. The feature contains no dark zone.

Feature: CN-58

Location: 31.470763, -111.282426

Date: February 6, 2024

Observations: This feature is an adit with a 4’Wx3’H portal opening. The adit opens into standing height, extends straight back 80’, and then ends in solid rock. Historical artifacts include an aluminum mineral sampling tag with flagging, a glass bottle, and drill holes. Bat sign documented was light guano scatter, moth wings, and beetle/cricket parts. A handful of guano pieces and insect parts were seen at the face of the mine, indicating this feature is lightly used as a night roost. Other wildlife sign seen was javelina scat and prints, a javelina jawbone, mouse scat, feathers, and bird guano. The javelina use of this feature was very high and that (along with seasonal water) could possibly obscure other bat sign within feature.

Bat Habitat: Moderate

Closure Recommendation: Leave As Is (LAI)

This feature presents no obvious structural concerns or internal physical hazards. LAI would provide the least impact to wildlife using this feature and preserve habitat for large wildlife that would otherwise be excluded by standard bat gates or destructive closure.

Feature: CN-59 / CN-59b / CN-59c / CN59d

Location: 31.46354291, -111.26752941 (CN-59)

31.46352503, -111.2675525 (CN-59b)

31.46352432, -111.2676213 (CN-59c)

31.46357774, -111.2676815 (CN-59d)

Date: January 23, 2024

Observations: This feature is an adit/shaft complex. CN-59d was the access point to the mine workings and sits at the end of a 16’ long trench. The workings extend east underneath CN-59c (a large skylight that is 10’ deep) and end at CN-59b and CN-59. This feature is very open and exposed, making the subterranean climate similar to the ambient air, and no true dark zone exists. The historical artifacts of this site contain a stacked rock wall near the entrance of CN-59d. There was also lots of trash from people migrating through. This included plastic bottles, medicine, food wrappers, clothing, blankets, and a propane can. No bat sign was seen within feature. A live horned lizard was also seen in the feature.

Bat Habitat: Marginal

Closure Recommendation:

CN-59: Destructive Closure, Warm Season (DCWS)

CN-59b: Destructive Closure, Warm Season (DCWS)

CN-59c: Destructive Closure, Warm Season (DCWS)

CN-59d: Destructive Closure, Warm Season (DCWS)

Feature: CN-60

Location: 31.464962, -111.263643

Date: February 6, 2024

Observations: This feature is an adit with a 4’Wx4’H portal opening. The adit is driven straight for 27’ and ends in solid rock. Bat sign for this feature includes light guano scatter, beetle/cricket parts, and moth wings, which indicates use as a night roost. Seasonal standing water could obscure any other sign within the adit. A mud wasp nest, dragonfly wings, rodent scat and nest, a kissing bug, spider webs, and red insect larvae were also observed in this feature.

Bat Habitat: Moderate

Closure Recommendation: Bat-compatible Closure, Any Time (BCAT)

Removal of vegetation in front of portal would help to open up the fly way for bats. A removable bar and a gate with 6” bar spacing is also recommended for this feature.

Feature: CN-61

Location: 31.464842, -111.263734

Date: February 6, 2024

Observations: This feature has a 6’Wx14’L collar and has an unknown depth. The feature was completely flooded at the time of the survey. Rails and other metal material are submerged in the feature. Since the feature is completely flooded, it could indicate that the workings are not very extensive. Lots of trash from migrating people was seen around the collar. These items include blankets, plastic bottles, razors, wall adapter, hats, clothes, slippers, and backpacks.

Bat Habitat: Unknown

Feature: CN-62

Location: 31.46421256, -111.25906535

Date: February 6, 2024

Observations: This feature contains 15’ of a previously collapsed adit that leads to two separate portals

(CN-62 and CN-62B) that do not intersect underground. The portal on the right is CN-62; it has a

5’Wx5’H portal opening and extends back 26’ feet, ending in solid rock. An underhand stope 10’ from the portal is about 10’ deep. The bottom of the stope contains 2’ of pooled water. An aluminum mineral sampling tag is nailed above the portal. This feature contains light guano scatter, which indicates bats use it as a day roost. Guano was seen before the stope, and the feature contains no true dark zone. A bird wing (possibly a crow) was seen at the face of the mine. Woodrat scat and small mammal scat were also observed.

Bat Habitat: Marginal

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious structural concerns or internal physical hazards.

Leaving this feature open is recommended to provide the least impact to wildlife using this feature.

Alternative Closure Recommendation: Destructive Closure, Warm Season (DCWS)

Feature: CN-62b

Location: 31.46421337, -111.2590675

Date: February 6, 2024

Observations: This feature is a shallow adit and is adjacent to CN-62. The adit has a portal opening

5’Wx3’H and extends back 10’, ending in solid rock. Moth wings, beetle/cricket parts, and light guano scatter were seen within the feature. Other wildlife sign documented was bird guano and woodrat scat.

Bat Habitat: Marginal

Closure Recommendation: Leave As Is (LAI)

This feature is remotely located and presents no obvious structural concerns or internal physical hazards.

Leaving this feature open is recommended to provide the least impact to wildlife using this feature.

Alternative Closure Recommendation: Destructive Closure, Warm Season (DCWS)

Feature: CN-63

Location: 31.464247, -111.267349

Date: January 23, 2024

Observations: This feature is a collapsed shaft; it contains no subterranean habitat and no dark zone.

Bat Habitat: None

This feature has self-remediated.

Feature: CN-64

Location: 31.462414, -111.244786

Date: February 8, 2024

Observations: This feature is an adit with a 5’Wx3’H portal opening. The adit is driven straight for 34’ and ends in solid rock. Two historical nails were seen within the feature. Lots of trash from migrating people was also present and included blankets, water bottles, plastic bags, and food packaging. Bat sign seen in the feature was light guano scatter, possible splatter, beetle/cricket parts, and moth wings. Guano and insect parts were seen near the entrance, indicating that this feature is primarily used as a night roost. Other wildlife sing includes heavy woodrat scat, javelina scat, a mouse nest, a cocoon, spider webs, and small mammal scat (possibly ringtail).

Bat Habitat: Marginal

Feature:…