PKAA, Twin Sisters Mine Closure Project

The State of Colorado Division of Reclamation, Mining and Safety (DRMS) is soliciting competitive bids for restoration and reclamation services under the Twin Sisters Mine Closure Project (DQ1 PKAA 2026*0289) located in western Boulder County near Nederland at elevations between 7,000 and 9,000 feet. The project encompasses safeguarding 26 mines and 2 maintenance mines that were operated from the 1860s through the mid-1960s for tungsten, gold, and silver extraction, addressing active collapse hazards on U.S. Forest Service land, Boulder County land, and private mining claims in an area frequented by recreational users. The scope of work includes backfilling 20 mine features with imported machine backfill and native material, installing 1 monolithic plug, installing 3 corrugated steel pipes with bat ladders, installing 1 vertical bat grate, installing 1 native rock bulkhead with bat access, and maintaining 2 additional features, supplemented by sediment control measures totaling 675 linear feet of biodegradable wattle. Primary deliverables include project mobilization and demobilization, safety and environmental planning, safeguarding hazardous mine openings across multiple phases, and maintenance of existing features, with specific closure methods defined for each of 23 individual mine features detailed in the bid schedule. Bidders must submit electronic bids via Colorado VSS containing completed bid schedules with unit pricing or lump-sum costs for all line items, a list of equipment offered, and acknowledgment of all addenda by the deadline of June 1, 2026 at 4:00 p.m. Mountain Time, with bid opening scheduled for June 2, 2026. A mandatory pre-bid meeting was held on January 28-31, 2026 (dates vary across documents), with written inquiries required to be submitted by email between January 9-February 2, 2026 at 12:00 p.m. The project is subject to Davis-Bacon federal prevailing wage requirements, with Amendment 1 issued on May 19, 2026 extending the original closing date from May 26, 2026 and revising the bid schedule and special conditions based on a pre-bid meeting.

This solicitation contains no identified set-asides for disadvantaged enterprises, minority-owned businesses, women-owned businesses, or other restricted categories of organizations, and all responsible bidders meeting the technical and financial qualifications are eligible to submit proposals. No incumbent vendors or current contractors are identified in the available solicitation documents, nor are there references to existing infrastructure or technology requiring integration into the project scope. The contract amount is established at $169,196.63, with the service period varying across documents but generally reflecting a completion window between June 2026 and September 2026, and extending through 2027 in some references. Deliverables must be shipped and billed to the Division of Reclamation, Mining and Safety at 1313 Sherman Street, Room 215, Denver, Colorado 80203. All inquiries regarding the solicitation should be directed to Teresa Donaldson at teresa.donaldson@state.co.us or 303-866-3567 extension 8149. Bidders must demonstrate capability to operate heavy equipment, manage environmental and sediment control measures in mountainous terrain, install specialized mine closure systems including grated pipes and bat access features, and comply with federal and state safety requirements including the Safety and Health Environmental Assessment Plan (SHEAP).