GM 3123 Final Geo Recommendations Swiftcurrent Rehabilitation.pdf

158377846

M E M O R A N D U M

Western Federal Lands Highway Division 610 E. Fifth Street

Vancouver, WA 98661

DATE: October 16, 2023

TO: Michael Traffalis Project Manager

FROM: Leah Wilmot Geotechnical Engineer

SUBJECT: Geotechnical Memo 3123 Final Geotechnical Recommendations Swiftcurrent Spur Road Rehabilitation

MT NP GLAC 14(6)

Glacier County, Montana

INTRODUCTION

This memorandum provides geotechnical investigation results, design, and construction recommendations for the Swiftcurrent Spur Road Rehabilitation Project being performed for Glacier National Park in Montana. The project stationing referenced in this report is from 30% Design Set, dated June 2023.

Project Description

The geotechnical scope of work for this project included a literacy review, a visual reconnaissance along the proposed alignment and a subsurface investigation program consisting of two subgrade borings. The subgrade borings, and laboratory testing was completed by Western Federal Lands Highway Division (WFL) and a subcontractor.

This memorandum was prepared to provide geotechnical recommendations for roadway rehabilitation design and construction considerations.

This memorandum supersedes all other previous memorandums for this project.

PROJECT DESCRIPTION

The project is located in Glacier National Park on Swiftcurrent Spur Road in Glacier County, Montana as shown in Figure 1 Regional Map. The project starts at the Swiftcurrent Motor Inn Parking Area at stationing 15+98 and ends at stationing 66+65 near the intersection of Swiftcurrent Spur Road and Many Glacier Loop Road.

Swiftcurrent Spur Road Rehabilitation October 2023

Figure 1 Regional Map

The project consists of rehabilitating 0.96 miles of existing asphalt pavement covered road, construction of a pedestrian path, the addition of a new parking lot, and adding new parking spaces along the alignment as seen in Figure 2.

Figure 2 Vicinity Map

Previous Work

HDR Engineering by Shannon and Wilson conducted a geotechnical investigation that included geotechnical borings along the Swiftcurrent Spur Road in 2022 (Shannon and Wilson, 2022).

This geotechnical investigation was conducted for GNP as part of the National Park Headquarters Wastewater System Improvements and the Swiftcurrent Water Distribution System Replacement Project.

A total of eight geotechnical borings were drilled at the Swiftcurrent site. Of those eight geotechnical borings, two, SW-12 and SW-11, were drilled along the currently proposed alignment for this project a seen in Figure A-1 in Appendix A on June 6, 2022, and June 8, 2022.

Geotechnical boring SW-11 was advanced to a depth of 11.5 feet bgs. The boring encountered 1-inch of asphalt overlying loose to dense, poorly graded gravel with silt and sand. Groundwater was encountered at 5.3 feet bgs at this location.

Geotechnical boring SW-12 was advanced to a depth of 11.5 feet below ground surface (bgs).

The boring encountered 3-inches of asphalt overlying medium dense silty sand with gravel.

Medium dense to dense poorly graded gravel with clay and sand was underlying the above silty sands.

Geotechnical boring locations of SW-11 and SW-12 can be seen in Appendix A.

GEOLOGY

The project is located in a region of varied geologic processes and forces. The principal natural architects of the current geologic scene have been the geologic history that created the rock types in the area, the mountain building forces that created the tremendous vertical relief, especially near the west end of Many Glacier Road, and the glaciation that carved the huge U-shaped valley and left lakes and extensive deposits of silty and clayey gravel in the bottom and sides of the Swiftcurrent/Many Glacier Valley.

Thrust faulting was a major factor in creating the mountainous terrain and was directly responsible for reversing the normal positions of younger rocks overlying older rocks. The west-to-east upward angle of thrust faulting in the eastern part of Glacier National Park has brought much older, relatively hard metasedimentary rocks from deep within the earth’s crust and placed them on top of younger, relatively soft sedimentary rocks. Geologists have interpreted the age difference between the two rock masses to be over 500 million years. This feature extends for tens of miles along the entire east side of Glacier National Park and is known as the Lewis Thrust Fault.

Paul Carrara (1990) mapped the surficial geology within the GNP. The mapping along the project alignment shows till (t3) as seen in Figure 3 Surficial Geology of Glacier National Park by Carrara (1990). The “t3” unit is dated to be late Pleistocene and is described as unsorted subrounded to subangular boulder rubble, consisting mainly of Belt Supergroup rocks and minor amounts of sand, silt, and clay. This unit is found on valley floors within mountainous areas where it was deposited as ground moraine by local mountain glaciers.

Figure 3 Surficial Geology of Glacier National Park by Carrara (1990)

Geologic Hazards

There are no mapped geologic hazards within the project’s vicinity. The closest mapped fault is the Mission fault which is approximately 50 miles southwest of the project vicinity near Kalispell, Montana (USGS, 2023).

SITE CONDITIONS

The project is located along the northern Rocky Mountains front range and elevation ranges from approximately 4,900 feet near the intersection of Swiftcurrent Spur Road and Many Glacier Loop Road to about 4940 feet at the Swiftcurrent Motor Inn. The mountains surrounding the Swiftcurrent Valley are dramatically steep and rises to an elevation of up to approximately 9,250 feet at Mt. Wilbur.

The Swiftcurrent Spur Road is located on the south facing slope of the valley floor. The valley consists of quaking aspen groves, wild grasses and deciduous forest that transitions into a montane forest near the Swiftcurrent Motor Inn. The north slopes along the roadway consist of exposed shear rocks faces compromised of the Belt Supergroup.

The two subgrade borings, located north of the existing Swiftcurrent Motor Inn parking lot, encountered topsoil and duff thickness of approximately 0.3- to 0.6-inches. Topsoil is defined as surficial soil layers that contain sufficient amounts of organic materials, including peat, rootlets, and plant matter to be classified as unsuitable materials in Section 101 of the FP-14 (FHWA, 2014). In general, the area is covered in thick vegetation, including liverworts and mosses, in addition to numerous trees and stumps.

The Federal Lands Highway (FLH) Pavement Evaluation Report (Nassim, 2022) that encompassed the Swiftcurrent Spur Road Rehabilitation Project noted that the pavement along the Swiftcurrent Spur Road was moderately damaged with observed pavement edge deterioration, rutting and minor cracking. The Swiftcurrent Parking Area was observed to have large amounts of standing water and debris from poorly drained runoff. The pavement was observed to be moderately damaged with slippage cracks, raveling, and polished aggregate (Western Federal Lands Highway Division, 2022).

Average Temperatures and Precipitation

The project site has a highly variable climate. The winter months see cold temperatures and snow cover the entire season that transition into warmer, rainier springs. Summer months are typically hot during the day and have cooler temperatures at night. During the fall, temperatures again become colder with snow possible by mid-September (NPS, 2023). Table 1 Climate Data Summary shows the average maximum and minimum temperatures, average monthly precipitations, and the average monthly snowfall data for the period of 1906 to 2011 for the Many Glacier, Montana USC00245361 weather station (Western Region Climate Center, 2023).

Table 1 Climate Data Summary Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

Avg.

Max.

Temp.

(F)

22.8 34 37.1 46.6 56.5 64.8 72.5 70.8 61.1 46.7 36.4 28 48.1

Avg.

Min.

Temp.

(F)

2.8 17.2 20.4 29.2 36.5 42.1 45.1 44.3 39.5 31.3 21.2 11.1 28.4

Avg.

Total

Precip.

(in.)

5.47 2.71 3.66 1.82 3.57 4.9 1.82 2.09 3 3.3 3.11 5.35 40.8

Avg.

Total

Snowfall (in.)

63 21.1 36.6 21 5 1.5 0 0 1.5 8.8 18.9 33.1 210.5

Avg.

Snow Depth (in.)

No Data

Note: Period of Record: 1906 to 2011 USC00245361, Western Region Climate Center (2023)

SUBSURFACE CONDITIONS

Under the direction of WFL, SK Geotechnical drilled a total of two subgrade borings (BH-01-SC and BH-02-SC) in 2023 in the area of the proposed new parking area west of the Swiftcurrent Motor Inn. The subgrade borings were drilled to a depth of 5.5 below ground surface (bgs) on

May 24, 2023. The approximate locations of the subgrade borings and the approximate coordinates can be viewed in the investigation map in Appendix A and below in Table 2. The boring logs are included in Appendix B.

Table 2 Subgrade Boring Approximate Locations

Subgrade Boring

Coordinates

Latitude Longitude

BH-01-SC 48.79774 -113.67818

BH-02A-SC 48.798024 -113.677868

The geotechnical subgrade borings were performed in native soils to the west of the Swiftcurrent Motor Inn and north of the existing Swiftcurrent Parking Area. Drilling methods during the investigation included the use of a 12-inch power augur to advance the subgrade borings.

Large grab bag samples and moisture samples were obtained for each change in strata.

Test borings were logged in the field by SK Geotechnical. Disturbed soil samples were collected and delivered to WFL in Vancouver, Washington, where samples and draft test boring logs were reviewed by a WFL geotechnical engineer or engineering geologist. Following review, selected samples of soil were submitted to the WFL Materials Laboratory for testing. Final test boring logs were modified as necessary to reflect additional information from laboratory testing.

The Federal Lands Highway Soil Description and Identification Guidelines and Federal Lands Highway Rock Characterization Guidelines are used to characterize soil units encountered during drilling operations. The USCS, as outlined in ASTM 2487 and ASTM 2488, was utilized in subgrade boring logs and is based on distribution and behavior of fine-grained and coarse-grained soil constituents. Soil and rock descriptive terms and the USCS chart is provided in the Descriptive Terminology for Boring Logs at the beginning of Appendix B.

Laboratory Materials Testing

Laboratory test results were completed for select soil samples for the subgrade borings.

Laboratory tests consisted of soil testing to characterize subsurface materials and characterize engineering properties of soils that may be encountered during construction. A summary of laboratory testing can be found in Tables C-1 of Appendix C, along with individual sample laboratory test results provided in Appendix C.

SUBSURFACE CONDITIONS

This section provides a synthesis of observed subsurface conditions during the subsurface investigation. No groundwater was encountered during the drilling of the subgrade borings.

Soil and Rock Types

In general, the subgrade borings encountered a peat layer, interpreted as topsoil overlying poorly graded gravel with silt and sand or poorly graded sand with silt and gravel.

In BH-01-SC, we encountered a peat layer to a depth of 6-inchs bgs. Underlying the peat layer, we encountered poorly graded gravel with silt and sand and trace cobbles to the terminating depth of 5.5 feet. In BH-02A-SC, we encountered a peat layer to a depth of 3.6-inches bgs.

Underlying this layer, we encountered poorly graded sand with silt and gravel to the terminating depth of 5.5-feet.

ANALYSIS

The above information was analyzed to determine design recommendations for parking lot and design and cut and fill slopes. The following sections provide our final recommendations for roadway design.

Cut Slopes

Cut slope areas are expected along the project alignment. Cuts slopes are anticipated to be approximately 10 feet or less. We recommended a cut slope inclination of 1V:2H along the alignment in soil. Anticipated soil conditions at cut slope locations include poorly graded gravels and sands. Exceptions to these recommendations are possible with the approval of the project Geotechnical Engineer if field conditions should warrant changes.

Please refer to the investigation logs in Appendix B for additional details, interpretations, and other data.

Soil Embankment Slopes

All other areas are considered embankment areas and should be generally limited to maximum slopes of 1V:2H with exceptions possible with the approval of the project Geotechnical Engineer. These slope angles assume the use of the on-site native poorly graded gravel and sand materials for embankment fill. These slopes should be designed for both temporary and permanent erosion control such as the use of a bonded-fiber hydromulch or rolled erosion control products (RECP). If layers of organics are encountered in the excavation it should not be used as embankment material.

CONSTRUCTION CONSIDERATIONS

Excavation

Observed topsoil depths are between 3.6- to 6-inches and will vary depending on the density of the vegetation at the location of the excavation. Conserve topsoil per 204.05 to be used on completed slopes per 624.

Based on the limited subgrade investigation and results of materials testing, excavated material may be reused for embankment construction, or may be processed to remove excessive fines and meet proper gradation as outlined under Section 704. – Soil. It is anticipated most material could be used as Unclassified Borrow (704.06). Reuse of excavated material can be considered to reduce the amount of waste and haul.

Processing of excavated material would require added space for material storage and processing on site with water during construction. Further, no subgrade samples were tested for durability, abrasion, weathering, and other tests for aggregate production suitability and mineral aggregate quality, so it is recommended aggregate testing be completed if uses other than Unclassified Borrow are considered.

As of the preparation of this memorandum, a suitable waste site has not been provided or identified by the County. Therefore, it will be the responsibility of the contractor to identify and procure a legal waste site in accordance with the contract.

Subgrade surfaces should consist of suitable materials to receive fill materials in preparation for a pavement section. Organics, loose soils, or other unsuitable materials should be removed from the locations. Subgrades should be covered immediately to prevent changes in moisture content or excessive drying, which could adversely affect the subgrade performance following construction.

If on-site moisture sensitive soils are encountered, they will be susceptible to disturbance and will generally provide inadequate support of construction equipment when the soil moisture content is above optimum and during wet weather conditions. These soils will be difficult to compact if they are over optimum moisture and use of vibratory compactors may cause pumping of subgrade soils. If pumping occurs, the soil should be dried to a moisture content near optimum (±2 percent of optimum moisture) and static compaction methods should be used.

Embankment

Minor embankments including sliver fills are planned for the project. We recommend planning for imported materials to be used in the embankment construction due to the types present in the majority of the roadway excavations.

During embankment preparation if ground conditions should differ from what is expected, the project Geotechnical Engineer should be contacted to assess the conditions for adverse effects on the design.

Material and Aggregate Sources

Imported fill materials are planned for select borrow, roadway aggregates and other materials.

As the preparation of this memorandum there is no Government provided material source for this project. It is the Contractor’s responsibility to locate an approved material source from an available commercial or private source for all construction materials that meet the requirements of the contract.

If suitable soils are encountered and the Contractor should desire to use the onsite materials, it will be the Contractor’s responsibility to ensure that the materials are processed to meet the contract requirements.

LIMITATIONS

This memorandum was prepared to provide geotechnical recommendations for the design and construction of the Swiftcurrent Spur Road Rehabilitation Project in Glacier National Park, Montana. Professional judgments and recommendations are presented in this memorandum.

They are based partly on evaluation of the technical information gathered and partly on the Geotechnical Team’s general experience with subsurface conditions in the area. It should be noted that the borings might not represent potentially unfavorable subsurface conditions between borings. The observed water levels and/or conditions may vary considerably, with time, according to the climate, rainfall, and other factors and are otherwise dependent on the duration of, and methods used in, and interpretations made form the subsurface investigation program.

If, during construction, soil conditions are encountered that vary from those discussed in this memorandum, or if project stationing, and/or configurations change, the WFL Geotechnical Team should be notified immediately in order to evaluate what effects, if any, the changes have on the recommendations contained in this memorandum. The recommendations presented in this report are applicable only to this specific site. These data are not to be used for other purposes.

REFERENCES

Carrara, P.E., 1990, Surficial geologic map of Glacier National Park, Montana, Miscellaneous Investigations Series Map I-1508-D, Scale 1:100,000

Federal Lands Highway, FP-14, (2014) Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects, U.S. Department of Transportation, Federal Highway Administration

National Park Service, Glacier National Park Montana, 2023, Weather: Weather - Glacier National Park (U.S. National Park Service) (nps.gov) (accessed September 2023).

Shannon and Wilson, 2022, “Preliminary Geotechnical Report, NPS Glacier National Park Headquarters and Swiftcurrent Utility Improvements”, Prepared for HDR Engineering Inc., dated December.

U.S. Geological Survey’s Interactive Quaternary Faults Database: U.S. Quaternary Faults (arcgis.com) (accessed September 2023).

Western Federal Lands Highway Division (WFLHD), 2022, DRAFT Pavement Evaluation Report, Rehabilitation of Two Medicine Road, Rehabilitation of Many Glacier Road from Hotel Intersection to Swiftcurrent Motor Inn, June 2022.

Western Regional Climate Center, 2023, Cooperative Climatological data summaries: MANY GLACIER, MONTANA - Climate Summary (dri.edu) ( September 2023)

Whipple, J.W., 1992, Geologic map of Glacier National Park, Montana, Miscellaneous Investigations Series Map I-1508-F, Scale 1:100,000.

CLOSING

Please contact Leah Wilmot at (360) 619-7697 or Leah.Wilmot@dot.gov with any questions regarding this memorandum.

CC: Michael Traffalis, Project Manager

Chris Conrad, Highway Design Geotechnical File

Attachments: Appendix A: Figures

Appendix B: Test Boring Logs Appendix C: Laboratory Test Reports

APPENDIX A

Figure A-1 Shannon and Wilson Boring Locations Figure A-2 Subgrade Investigation Map

0 300 600

Approximate Scale In Feet

GLCA 307440 & 307606

NPS Glacier National Park

Flathead and Glacier Counties, Montana

SWIFTCURRENT

SITE AND EXPLORATION PLAN

FIG. 3

December 2022 107857-001

SHANNON & WILSON, INC.

Geotechnical and Environmental Consultants

Fishercap Lake

Swiftcurrent Creek

W ilb ur C re ek

Service Road

Loop Road

Route 3

SW-09

SW-10

SW-11

SW-12

SW-13

SW-14 SW-15

SW-16

N

LEGEND

&< Approximate Boring Location and DesignationSW-03

Headquarters

Swiftcurrent

National Geographic, Esri, Garmin, HERE, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, increment P Corp., Maxar

Many Glacier Campground

Existing Tank Location

Proposed Tank Location

Horizontal Directional Drilling Location

NPS Administration Area

Chlorination Building

Swiftcurrent Motor Inn

Altyn Peak

Figure A-1: Shannon and Wilson Subsurface Exploration Map showing locations of SW-12 and SW-13. (Shannon and Wilson, 2022)

Western Federal Lands Highway Division 610 East Fifth Street Vancouver, WA 98661

Project No. Subgrade Investigation Map Figure A‐2MT NP GLAC 14(6) Scale

BH‐02A‐SC and BH‐01‐SC N/A File Name:

N/A Date:

September 2023

APPENDIX B

B-1 Test Boring Logs

B-2 Shannon and Wilson 2022 Boring Logs

APPENDIX B-1

Test Boring Logs

Project Name: Swift Current Motor Inn Parking Lot Expansion Project Location: Glacier National Park, Montana

Fracture Frequency (fractures per foot) Percent Passing No. 200 Sieve Liquid Limit (%) Non-Plastic Plastic Limit (%) Pocket Penetrometer Reading Rock Core Recovery Rock Quality Designation Specific Gravity Unconfined Compressive Strength Vibrating Wire Piezometer Water Content (%)

BORING LOG LEGEND

DRILLING METHOD SYMBOLS

SAMPLE TYPE SYMBOLS

Grab Sample

Hollow Stem Auger

ABBREVIATIONS

FF

Fines

LL

NP

PL

PP

Rec

RQD

SG

UC

VWP

WC

U. S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

FEDERAL LANDS HIGHWAY DIVISION

F H

W A

B O

R

IN

G L

O G

L E

G E

N D

F

H W

A _D

A T

A T

E M

P

LA

T E

_2

.G

D T

/1 5/

:0

D :\T

W O

M E

D A

N D

S W

IF

T

C U

R R

E N

T \4

3.

G P

J ow er a ug er to

.5 '/1

2"

Fines = 7%

PEAT, black, moist. Topsoil.

0.5 ft Poorly graded GRAVEL with silt and sand (GP-GM), gray, fine gravel to coarse gravel, angular to subangular, trace cobbles. A-1-a (0).

5.5 ft Bottom of borehole at 5.5 ft.

D ril lin g

M et ho d

Field Blow Count (Recovery)No.

T yp e

Test Results

SAMPLE

BH-01-SC

Sheet: 1 of 1

Project Location: Glacier National Park, Montana

20 40 60 80

PL LLWC

N VALUE

20 40 60 80

Project Name: Swift Current Motor Inn Parking Lot Expansion D ep th ft)

MATERIAL DESCRIPTION

BORING LOG

U. S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

FEDERAL LANDS HIGHWAY DIVISION

F H

W A

L O

G

F H

W A

_D A

T A

T E

M P

LA

T

E .G

D T

/1 5/

:0

D :\T

W O

M E

D A

N D

S W

IF

T

C U

R R

E N

T \4

3.

G P

J

Groundwater Depth:

Notes:

After Drilling: No Groundwater Encountered

While Drilling: No Groundwater Encountered At Completion: No Groundwater Encountered

Moved 2' east of original staked location due to tree stumps.

Latitude: 48.79774° Longitude: -113.67818° Date Started: 5/24/23 Date Completed: 5/24/23 Driller/Company: E. Hollibaugh/SK Geotechnical

Logger/Company: C. Binstock/SK Geotechnical

Drill CME-75HT Hammer Type: NA

NP

G ra ph ic

L og ow er a ug er to

.5 '/1

2"

Fines = 6%

PEAT, black, moist. Topsoil.

0.3 ft

Poorly graded SAND with silt and gravel (SP-SM), gray, fine sand to coarse sand, angular to subangular, A-1-a (0).

5.5 ft Bottom of borehole at 5.5 ft.

D ril lin g

M et ho d

Field Blow Count (Recovery)No.

T yp e

Test Results

SAMPLE

BH-02A-SC

Sheet: 1 of 1

Project Location: Glacier National Park, Montana

20 40 60 80

PL LLWC

N VALUE

20 40 60 80

Project Name: Swift Current Motor Inn Parking Lot Expansion D ep th ft)

MATERIAL DESCRIPTION

BORING LOG

U. S. DEPARTMENT OF TRANSPORTATION

FEDERAL HIGHWAY ADMINISTRATION

FEDERAL LANDS HIGHWAY DIVISION

F H

W A

L O

G

F H

W A

_D A

T A

T E

M P

LA

T

E .G

D T

/1 5/

:0

D :\T

W O

M E

D A

N D

S W

IF

T

C U

R R

E N

T \4

3.

G P

J

Groundwater Depth:

Notes:

After Drilling: No Groundwater Encountered

While Drilling: No Groundwater Encountered At Completion: No Groundwater Encountered

Moved 26.5' east and 33.5' north of orginal staked location due to sloping terrain and trees.

Latitude: 48.798024° Longitude: -113.677868° Date Started: 5/24/23 Date Completed: 5/24/23 Driller/Company: E. Hollibaugh/SK Geotechnical

Logger/Company: C. Binstock/SK Geotechnical

Drill CME-75HT Hammer Type: NA

NP

G ra ph ic

L og

APPENDIX B-2

Shannon and Wilson 2022 Boring Logs

0.1

11.5 S

-1 S

-2 S

-3 S

-4

1 inch of Asphalt

Loose to dense, red-brown, Poorly Graded Gravel with Silt and Sand (GP-GM); moist.

Till

BOTTOM OF BORING

COMPLETED ON 06/08/2022

G ro un dw at er n ot e nc ou nt er e d du ri ng d ri lli ng

Hollow-Stem Auger Vine Laboratories CME 75 Truck Rig

LEGEND

Drilling Method:

Drilling Company:

Drill Rig Equipment:

Other Comments:

SOIL DESCRIPTION

GLCA 307440 & 307606

NPS Glacier National Park

Flathead and Glacier Counties, Montana

D ep th , f t.

Latitude:

Longitude:

Station:

Offset:

20 40

Standard Penetration Test

LOG OF BORING SW-11

6 in.

AWJ

Automatic

December 2022

Sample Not Recovered

Hole Diam.:

Rod Type.:

Hammer Type:

SHANNON & WILSON, INC.

11.5 ft.

FIG. A-13

S am pl es

Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual.

FINAL

NOTES

S ym bo l

0 60

Total Depth:

Top Elevation:

Vert. Datum:

Horiz. Datum:

20 40

Geotechnical and Environmental Consultants

107857-001

G ro un d

W at er

D ep th , f t.

1. Refer to Figures A-1 and A-2 for explanation of symbols, codes, abbreviations and definitions.

2. The stratification lines represent the approximate boundaries between soil types, and the transition may be gradual.

3. The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials.

4. Groundwater level, if indicated above, is for the date specified and may vary.

5. USCS designation is based on visual-manual classification and selected lab testing.

6. The hole location was measured from existing site features and should be considered approximate.

M A

S T

E R

_L O

G _E

_P O

C K

E T

P E

N _L

A T

LO

N G

7-

N P

S G

LA

C

IE

R

N P

.G P

J D

E N

V E

R

.G D

T

/2 5/

140 lbs / 30 inches (blows/foot)PENETRATION RESISTANCE

Hammer Wt. & Drop:

% Fines % Water Content

(<0.075mm)

0.3

4.5

11.5 S

-1 S

-2 S

-3 S

-4

3 inches of Asphalt

Medium dense, brown, Silty Sand with Gravel (SM); moist.

Till

Medium dense to dense, brown, Poorly Graded Gravel with Clay and Sand (GP-GC); moist.

Till

BOTTOM OF BORING

COMPLETED ON 06/06/2022

G ro un dw at er n ot e nc ou nt er e d du ri ng d ri lli ng

Hollow-Stem Auger Vine Laboratories CME 75 Truck Rig

LEGEND

Drilling Method:

Drilling Company:

Drill Rig Equipment:

Other Comments:

SOIL DESCRIPTION

GLCA 307440 & 307606

NPS Glacier National Park

Flathead and Glacier Counties, Montana

D ep th , f t.

Latitude:

Longitude:

Station:

Offset:

20 40

Standard Penetration Test

LOG OF BORING SW-12

6 in.

AWJ

Automatic

December 2022

Sample Not Recovered

Hole Diam.:

Rod Type.:

Hammer Type:

SHANNON & WILSON, INC.

11.5 ft.

FIG. A-14

S am pl es

Refer to the report text for a proper understanding of the subsurface materials and drilling methods. The stratification lines indicated below represent the approximate boundaries between material types, and the transition may be gradual.

FINAL

NOTES

S ym bo l

0 60

Total Depth:

Top Elevation:

Vert. Datum:

Horiz. Datum:

20 40

Geotechnical and Environmental Consultants

107857-001

G ro un d

W at er

D ep th , f t.

1. Refer to Figures A-1 and A-2 for explanation of symbols, codes, abbreviations and definitions.

2. The stratification lines represent the approximate boundaries between soil types, and the transition may be gradual.

3. The discussion in the text of this report is necessary for a proper understanding of the nature of the subsurface materials.

4. Groundwater level, if indicated above, is for the date specified and may vary.

5. USCS designation is based on visual-manual classification and selected lab testing.

6. The hole location was measured from existing site features and should be considered approximate.

M A

S T

E R

_L O

G _E

_P O

C K

E T

P E

N _L

A T

LO

N G

7-

N P

S G

LA

C

IE

R

N P

.G P

J D

E N

V E

R

.G D

T

/2 5/

140 lbs / 30 inches (blows/foot)PENETRATION RESISTANCE

Hammer Wt. & Drop:

% Fines % Water Content

(<0.075mm)

APPENDIX C

Laboratory Test Reports

Table C‐1 : 2021 Laboratory Testing Summary

88.9mm 76mm 63.5mm 50mm 37.5 25.0mm 19.0mm 12.5mm 9.5mm 4.75mm 2.00mm 425µm 75µm 20µm 10μm 5µm 2µm 3 1/2" 3" 2 1/2" 2" 1 1/2" 1" 3/4" 1/2" 3/8" #4 #10 #40 #200 20µm 10μm 5µm 2µm

ft. % % % % % % % % % % % % % % % % % % % % % BH‐01‐SC 162 2.0‐5.5 100.0 98.4 98.4 93.2 88.8 82.7 76.4 68.1 63.3 51.0 43.3 18.8 7.2 5.0 4.0 3.0 1.8 58.7 22.5 11.6 7.2 BH‐02A‐SC 165 0.5‐5.5 ‐ ‐ 100.0 95.4 91.3 83.5 78.3 70.1 65.4 54.0 43.6 21.8 6.1 4.4 3.7 2.6 1.6 56.4 21.9 15.6 6.1

SAMPLE

DEPTH

LL PL PI

ft. ‐ ‐ ‐

BH‐01‐SC 161 2.0‐2.5 ‐ ‐ ‐

BH‐01‐SC 162 2.0‐5.5 NP NP NP

BH‐01‐SC 163 5.0‐5.5 ‐ ‐ ‐

BH‐02A‐SC 164 2.0‐2.5 ‐ ‐ ‐

BH‐02A‐SC 166 5.0‐5.5 ‐ ‐ ‐

BH‐02A‐SC 165 0.5‐5.5 NP NP NP

AASHTO FRACTIONSPARTICLE SIZE

Poorly‐graded GRAVEL with silt, sand, and cobbles or boulders, or both (GP‐GM)

Poorly‐graded sand with silt and gravel (SP‐SM)

UNIFIED SOIL CLASSIFICATION SYSTEM (USCS)

AASHTO

CLASSIFICATION

SILT‐CLAY

SAMPLE

DEPTH

BORING

NO.

FIELD

SAMPLE NO.

FINE

SAND

Gravel

COARSE

SAND

BORING

NO.

FIELD

SAMPLE NO.

APPARENT SPECIFIC

GRAVITY

Moisture

‐ ‐8

7.5 ‐ ‐

A‐1‐a (0)

7.5 ‐ ‐

‐ 2.664 A‐1‐a (0)

‐ 2.704

5.8

Western Federal Lands

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0847-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Table of Contents

Station:

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 161

Lot No.:

Date Sampled: 5/24/2023

Depth: 2.0'-2.5' Hole No.: BH-01-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

W-23-0847-GS _________________________________________________________________ 2

Station:

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0847-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 161

Lot No.:

Date Sampled: 5/24/2023

Depth: 2.0'-2.5' Hole No.: BH-01-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

Unit of MeasureResult

Drying Temperature 230 ° F

Moisture Content 7.5 %

Methods: AASHTO T 265 Moisture Content of Soil Test Date: 7/14/2023 Tested By: Chuck Miller

Comments:

Test Validated By: Jerrad Isch Validated Date: 7/25/2023

Version 1

All reported results apply to the sample as received.

Page 2 of 2Sample ID: W-23-0847-GS

Con tro lle d C op y

Sample ID: W-23-0848-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Table of Contents

Station:

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 163

Lot No.:

Date Sampled: 5/24/2023

Depth: 5.0'-5.5' Hole No.: BH-01-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

W-23-0848-GS _________________________________________________________________ 2

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0848-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 163

Lot No.:

Date Sampled: 5/24/2023

Depth: 5.0'-5.5' Hole No.: BH-01-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

Unit of MeasureResult

Drying Temperature 230 ° F

Moisture Content 8.0 %

Methods: AASHTO T 265 Moisture Content of Soil Test Date: 7/14/2023 Tested By: Chuck Miller

Comments:

Test Validated By: Jerrad Isch Validated Date: 7/25/2023

Version 1

All reported results apply to the sample as received.

Page 2 of 2Sample ID: W-23-0848-GS

Con tro lle d C

Sample ID: W-23-0849-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/31/2023

Table of Contents

Station:

Material Description: SO-COM

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 162

Lot No.:

Date Sampled: 5/24/2023

Depth: 0.5-5.5' Hole No.: BH-01-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

W-23-0849-GS _________________________________________________________________ 2

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0849-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/31/2023

Material Description: SO-COM

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 162

Lot No.:

Date Sampled: 5/24/2023

Depth: 0.5-5.5' Hole No.: BH-01-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

Unit of MeasureResult

Specific Gravity @ 20°C 2.704

Methods: AASHTO T 100 - Specific Gravity of Soils Test Date: 7/28/2023 Tested By: Rob Lange

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

Version 1

Unit of MeasureResult

Liquid Limit From T 89 Not Run

Plastic Limit from T 90 Non-Plastic

Plasticity Index Not Applicable

Methods: AASHTO T 89 & T 90 - Atterberg Limits Test Date: 7/25/2023 Tested By: Rob Lange

Comments:

Test Validated By: Rob Lange Validated Date: 7/25/2023

Version 1

Unit of MeasureResult

6" sieve (152.4 mm) % Passing - %

5" sieve (127 mm) % Passing - %

4" sieve (101.6 mm) % Passing 100 %

3 1/2" sieve (88.9 mm) % Passing 100.0 %

Methods: AASHTO T 88 - Particle Size Analysis of Soils Test Date: 7/28/2023 Tested By: Rob LangeVersion 1

All reported results apply to the sample as received.

Page 2 of 4Sample ID: W-23-0849-GS

Con tro lle d C

Unit of MeasureResult

3" sieve sieve (76 mm) % Passing 98.4 %

2 1/2" sieve (63.5 mm) % Passing 98.4 %

2" sieve (50.0 mm) % Passing 93.2 %

1 1/2" sieve (37.5 mm) % Passing 88.8 %

1" sieve (25.0 mm) % Passing 82.7 %

3/4" sieve (19.0 mm) % Passing 76.4 %

1/2" sieve (12.5 mm) % Passing 68.1 %

3/8" sieve (9.5 mm) % Passing 63.3 %

No. 4 sieve (4.75 mm) % Passing 51.0 %

No. 10 sieve (2.0 mm) % Passing 41.3 %

No. 40 Sieve (0.425 mm) % Passing 18.8 %

No. 200 Sieve (0.075 mm) % Passing 7.2 %

Interpolated 0.020 mm % Passing 5.0 %

Interpolated 0.010 mm % Passing 4.0 %

Interpolated 0.005 mm % Passing 3.0 %

Interpolated 0.002 mm % Passing 1.8 %

Interpolated 0.001 mm % Passing - %

D10 0.1135 mm

D30 0.9179 mm

D50 4.3503 mm

D60 7.9058 mm

CU 69.635

CC 0.939

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

Unit of MeasureResult

Classification A-1-a (0)

Gravel (2.00 mm and larger) 58.7 %

Coarse sand (2.0 to 0.42 mm) 22.5 %

Fine Sand (0.42 to 0.074 mm) 11.6 %

Silt-clay (0.075mm and smaller) 7.2 %

Methods: AASHTO M 145 - Classification (AASHTO M 145 is not an AAP accredited test)

Test Date: 7/28/2023

Tested By: Rob Lange

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

Version 1

Methods: ASTM D 2487 - Unified Soil Classification System Test Date: 7/28/2023 Tested By: Rob LangeVersion 1

All reported results apply to the sample as received.

Page 3 of 4Sample ID: W-23-0849-GS

Con tro lle d C

Classification

GP-GM, Poorly graded gravel with silt with sand with cobbles or boulders, or both

Fine Gravel (19.0 to 4.75 mm) 25 %

Coarse Sand (4.75 to 2.00 mm) 10 %

Medium Sand (2.00 to 0.425 mm) 22 %

Fine Sand (0.425 to 0.075 mm) 12 % Silt (0.075 mm and smaller w/ PI < 4 and below the A line) - %

Clay (0.075 mm and smaller w/ PI ≥ 4 and above the A line) 7 %

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

All reported results apply to the sample as received.

Page 4 of 4Sample ID: W-23-0849-GS

Con tro lle d C

Sample ID: W-23-0850-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Table of Contents

Station:

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 164

Lot No.:

Date Sampled: 5/24/2023

Depth: 2.0'-2.5' Hole No.: BH-02A-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

W-23-0850-GS _________________________________________________________________ 2

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0850-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 164

Lot No.:

Date Sampled: 5/24/2023

Depth: 2.0'-2.5' Hole No.: BH-02A-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

Unit of MeasureResult

Drying Temperature 230 ° F

Moisture Content 5.8 %

Methods: AASHTO T 265 Moisture Content of Soil Test Date: 7/14/2023 Tested By: Chuck Miller

Comments:

Test Validated By: Jerrad Isch Validated Date: 7/25/2023

Version 1

All reported results apply to the sample as received.

Page 2 of 2Sample ID: W-23-0850-GS

Con tro lle d C

Sample ID: W-23-0851-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Table of Contents

Station:

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 166

Lot No.:

Date Sampled: 5/24/2023

Depth: 5.0'-5.5' Hole No.: BH-02A-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

W-23-0851-GS _________________________________________________________________ 2

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0851-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/27/2023

Material Description: T 265 - Moisture Content of Soils

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 166

Lot No.:

Date Sampled: 5/24/2023

Depth: 5.0'-5.5' Hole No.: BH-02A-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

Unit of MeasureResult

Drying Temperature 230 ° F

Moisture Content 7.5 %

Methods: AASHTO T 265 Moisture Content of Soil Test Date: 7/14/2023 Tested By: Chuck Miller

Comments:

Test Validated By: Jerrad Isch Validated Date: 7/25/2023

Version 1

All reported results apply to the sample as received.

Page 2 of 2Sample ID: W-23-0851-GS

Con tro lle d C

Sample ID: W-23-0852-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/31/2023

Table of Contents

Station:

Material Description: SO-COM

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 165

Lot No.:

Date Sampled: 5/24/2023

Depth: 0.5-5.5' Hole No.: BH-02A-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

W-23-0852-GS _________________________________________________________________ 2

Project No.: MT NP GLAC 14(6) Sample ID: W-23-0852-GS

Materials Laboratory

ISO/IEC 17025:2017 Accredited Date Distributed: 07/31/2023

Material Description: SO-COM

MilePost:

Offset:

Intended Use:

Remarks:

Source Name:

Source Location:

Sample Location: Other

Submitted By: Leah Wilmot

Quantity Represented:

Item No.:

Field Sample No.: 165

Lot No.:

Date Sampled: 5/24/2023

Depth: 0.5-5.5' Hole No.: BH-02A-SC

Project Name: SWIFTCURRENT SPUR ROAD

REHABILITATION

Unit of MeasureResult

Specific Gravity @ 20°C 2.664

Methods: AASHTO T 100 - Specific Gravity of Soils Test Date: 7/28/2023 Tested By: Rob Lange

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

Version 1

Unit of MeasureResult

Liquid Limit From T 89 Not Run

Plastic Limit from T 90 Non-Plastic

Plasticity Index Not Applicable

Methods: AASHTO T 89 & T 90 - Atterberg Limits Test Date: 7/25/2023 Tested By: Rob Lange

Comments:

Test Validated By: Rob Lange Validated Date: 7/25/2023

Version 1

Unit of MeasureResult

6" sieve (152.4 mm) % Passing - %

5" sieve (127 mm) % Passing - %

4" sieve (101.6 mm) % Passing - %

3 1/2" sieve (88.9 mm) % Passing - %

Methods: AASHTO T 88 - Particle Size Analysis of Soils Test Date: 7/28/2023 Tested By: Rob LangeVersion 1

All reported results apply to the sample as received.

Page 2 of 4Sample ID: W-23-0852-GS

Con tro lle d C

3" sieve sieve (76 mm) % Passing - %

2 1/2" sieve (63.5 mm) % Passing 100.0 %

2" sieve (50.0 mm) % Passing 95.4 %

1 1/2" sieve (37.5 mm) % Passing 91.3 %

1" sieve (25.0 mm) % Passing 83.5 %

3/4" sieve (19.0 mm) % Passing 78.3 %

1/2" sieve (12.5 mm) % Passing 70.1 %

3/8" sieve (9.5 mm) % Passing 65.4 %

No. 4 sieve (4.75 mm) % Passing 54.0 %

No. 10 sieve (2.0 mm) % Passing 43.6 %

No. 40 Sieve (0.425 mm) % Passing 21.8 %

No. 200 Sieve (0.075 mm) % Passing 6.1 %

Interpolated 0.020 mm % Passing 4.4 %

Interpolated 0.010 mm % Passing 3.7 %

Interpolated 0.005 mm % Passing 2.6 %

Interpolated 0.002 mm % Passing 1.6 %

Interpolated 0.001 mm % Passing - %

D10 0.1151 mm

D30 0.7621 mm

D50 3.4061 mm

D60 6.8486 mm

CU 59.482

CC 0.737

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

Unit of MeasureResult

Classification A-1-a (0)

Gravel (2.00 mm and larger) 56.4 %

Coarse sand (2.0 to 0.42 mm) 21.9 %

Fine Sand (0.42 to 0.074 mm) 15.6 %

Silt-clay (0.075mm and smaller) 6.1 %

Methods: AASHTO M 145 - Classification (AASHTO M 145 is not an AAP accredited test)

Test Date: 7/28/2023

Tested By: Rob Lange

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

Version 1

Methods: ASTM D 2487 - Unified Soil Classification System Test Date: 7/28/2023 Tested By: Rob LangeVersion 1

All reported results apply to the sample as received.

Page 3 of 4Sample ID: W-23-0852-GS

Con tro lle d C

Classification SP-SM, Poorly graded sand with silt with gravel

Fine Gravel (19.0 to 4.75 mm) 24 %

Coarse Sand (4.75 to 2.00 mm) 10 %

Medium Sand (2.00 to 0.425 mm) 22 %

Fine Sand (0.425 to 0.075 mm) 16 % Silt (0.075 mm and smaller w/ PI < 4 and below the A line) - %

Clay (0.075 mm and smaller w/ PI ≥ 4 and above the A line) 6 %

Comments:

Test Validated By: Rob Lange Validated Date: 7/28/2023

All reported results apply to the sample as received.

Page 4 of 4Sample ID: W-23-0852-GS

Con tro lle d C

Pages from 2022-12 NPS Swift Current Geotech Rpt_.pdf