Attachment_1_-_SOW_-_Christenot_Mill_Stabilization.pdf

STATEMENT OF WORK (SOW) AND TECHNICAL SPECIFICATIONS

FOR

STABILIZATION OF THE HISTORIC CHRISTENOT MILL

VIRGINIA CITY, MT

JULY 2026

1. BACKGROUND

“Prospectors discovered gold in Alder Gulch, Idaho Territory, on May 26, 1863. Within weeks, the countryside was teeming with thousands of prospectors, but the easily extracted placer gold soon played out. B. F. Christenot, acting independently or perhaps as agent to Philadelphia backers, began acquiring claims in the Summit Mining District in 1864. Christenot later concealed a substantial amount of gold on his person and traveled to Philadelphia where he convinced investors to back construction of a mill. The transition from placer to lode mining, an expensive undertaking that required heavy financial backing, is well documented here at Union City. Machinery, transported in fifty-two ox-drawn wagons over the Bozeman Trail, arrived in October 1866. Thompson and Griffith of Virginia City constructed the mill, which operated by spring 1867. In June, journalist A. K. McClure arrived from the east to assume its management. Most milling of this period was accomplished by stamping, but the Union City operation employed a process using Chilean rollers for crushing the quartz. Although the mill was reported to be the most efficient in the territory, the ore was soon exhausted and the mill closed down in spring 1868.

Sixty thousand dollars was said to have been extracted from the company’s nearby Oro Cache lode, but the equipment alone cost $80,000; the operation was a financial disaster. At peak production the Christenot Mill employed up to forty workers, and the site, representing all aspects of gold milling technology from processing to management, fills a significant chapter in the history of mining in Montana.”

The Christenot Mill site is an impressive and peaceful place to behold a testament to good design and skilled trade work 150 years ago. The many and varied failing masonry sections are indicators of work needed to slow the ongoing process of the forest reclaiming its rubble.

Many masonry repairs have been carried out to varying degrees of success on the structure. A variety of modern mortar mixes and historic lime mortar construction have led to a patchwork of repairs that are at times both benefiting and depleting structural stability. Photos and reports from the last 25 years of repairs suggest the wrong set of mortar prescriptions were followed during recent stabilization efforts.

Christenot Mill was built with Natural Hydraulic Lime mortar and local sand. The lime was most likely produced by firing local limestone in nearby lime kilns. That limestone turned to lime would then have been slaked with water in a violent chemical reaction just to the point of creating a usable lime putty or powder but not slaked fully to the point of becoming modern hydrated lime, also called builder’s lime.

Natural Hydraulic Lime (natural hydraulic lime) has very different living properties, compared to builder’s lime. Natural hydraulic lime, when mixed with the proper ratios of sand and water, requires days to be cured under very specific conditions: damp, without freezing, without over-exposure to sun and wind. The resulting joints and walls, properly cured, breathe with the seasons and the changes in weather. Water is absorbed and evaporated, slowly inhaled and exhaled through the joints. The joints are autogenous in nature. They self-heal within reason due to the ongoing chemical curing that occurs with exposure to carbon dioxide. When a small crack occurs in the masonry wall, the newly exposed interior natural hydraulic lime mortar reacts to the carbon dioxide in the air, and forms a new skin, preventing the crack from expanding deeper into the wall.

The Bureau of Land Management’s (BLM) Dillon Field Office has been involved in preserving the structure and obtaining historical register status of the mill. Though the preservation strategy for the structure is to maintain a state of “Arrested Decay”, there have been several stabilization efforts throughout the past decades including windowsill renovations and patching mortar sections which have dissolved throughout the past century.

The BLM is requesting a contractor with specialization in Historic Preservation to complete stabilization efforts as described in the following Statement of Work. The stabilization work is to be performed between 8/15/2026 and 10/31/2028

2. DESCRIPTION OF SERVICES

Services consist of stabilization efforts based on the Technical Requirements found in Section IV and the associated condition assessment performed by a 3rd party in 2022. The contractor will be required to provide proof of historical preservation experience and past performance examples showing proficiency in the work requested. The contractor will be expected to work on a consolidated timeline, in conjunction with the BLM archaeologist and engineer, and remove all waste and debris from the project area after stabilization efforts have been completed.

A. Place of Performance:

i. Location – Christenot Mill, Ennis, MT 59729

ii. Coordinates- 45.220301, -111.914924 B. Site Conditions: Bureau of Land Management’s Christenot Mill – Dillon Field Office. Site is located along a natural surfaced roadway approximately 8 miles south of Virgina City. The site can be reached by a high-clearance 4-wheel drive vehicle or UTV. There is minimal parking and turnaround area near the site and the road must be kept open for public use throughout the duration of the project.

C. Period of Performance: Performance time for this contract is September 15th, 2026 – October 31st, 2028. Workdays are limited to Monday – Friday (Excluding Federal holidays) between the hours of 7:30 AM and 6:00 PM, unless otherwise arranged in advance with the Contracting Officer.

3. GENERAL INFORMATION

I. PAYMENT

A. Payment shall be made in one (1) lump sum at quoted price including the cost of all materials and delivery plus any and all costs associated with overhead, profit, etc.

II. GENERAL CONDITIONS

A. Qualifications: The contractor will possess the minimal professional qualifications for each discipline of work and provide proof of similar past performance experience within the past 5 years.

B. Scope of Services: The project includes furnishing all labor and materials as described in section III.

Contractors will possess all necessary licenses to accomplish the specified work. Equipment shall be in good working order and materials shall be inspected by the Contracting Officer’s Representative prior to installation.

C. Warranty: The Contractor warrants that the work performed under this conforms to the contract requirements and is free from any defect in equipment, material, design, finish, or workmanship performed by or the responsibility of the Contractor. Contractor shall warrant installed all materials and construction methods for a minimum of one-year from date of completion.

D. Cleanup and Disposal: The Contractor shall be responsible for solid waste disposal. The Contractor shall at all times keep the area in a clean, neat, and orderly condition. Construction related debris, including but not limited to used motor oil, oil cans, grease cartridges and refuse shall be removed promptly from the site and disposed of in a lawful manner off Bureau of Land Management lands.

Fees for the use of landfills or transfer stations shall be paid for by the Contractor if there is a charge.

III. SUBMITTALS

A. The contractor shall submit with quote information, a work plan & schedule along with any certifications and past performance examples within the past 5 years showing proficiency in shoring, bracing, and stabilizing efforts on historic structures.

4. TECHNICAL REQUIREMENTS

PROJECT DESCRIPTION & DELIVERABLES

I. PROJECT DESCRIPTION

This work consists of executing stabilization measures to address listing concerns as described in this Statement of Work to support and brace the Christenot Mill. The project goal is to restore the structural integrity while maintaining the historic character of the mill to the greatest extent possible. The contractor will be expected to utilize the 2022 Condition Assessment along with photographs and background information to implement stabilization measures to the structure. The contractor will be expected to submit a narrative describing their methods and means for performing the work. This narrative must meet all recommendations provided by the BLM and meet criteria specified by SHPO for maintenance of structures belonging to the Historical Register. Labor and construction supplies will be provided by the contractor. The contractor should source all sand materials approved locations near the site, as these materials best fit the historical nature of the original construction and have been approved for historical preservation construction.

Workdays will need to be scheduled between the contractor and The BLM 3 days in advance. There are many historic structures in the vicinity of the mill. These shall not be negatively impacted, permanently removed, or discarded without BLM knowledge. Any questions or comments can be directed to the BLM Archealogist, Joanna Bauer-Goldsmith, at 406-533-7655 or jbauergoldsmith@blm.gov.

mailto:jbauergoldsmith@blm.gov

II. PROJECT DELIVERABLES

A. Christenot Wall Stabilization

Hydraulic Lime Mortar Repair

*Perform wall repairs according to the recommendations described in 2022 condition assessment and per attached plans.

B. Drainage Ditch

Drainage Construction

*Construct drainage ditch 12” in depth and 12” in width in location staked by BLM.

END OF SECTION