State of Montana Newsroom
DEQ publishes final decision and Environmental Assessment for Columbia Gold Project
Department of Environmental Quality
HELENA—The Montana Department of Environmental Quality (DEQ) has approved an Exploration License Amendment from Sentinel Metals and issued a final Environmental Assessment (EA) for the Columbia Gold Project, near Lincoln, Montana in Lewis and Clark County.
DEQ accepted public comment from March 20, 2026, through April 13, 2026, on the draft EA for Sentinel Metal’s proposed amendment to the exploration license. In total, DEQ received 8,736 public comments from 1,713 individuals and corporations on the draft EA. Of those comments many were similar and 26 broad themes were identified and responded to as substantive comments. A substantive comment is relevant, fact-based, and specific and may offer insight, analysis, or constructive feedback on the draft document. All comments were reviewed by the agency and responses to the comments were incorporated into the final EA for the proposed exploration project.
Sentinel Metals posted a performance reclamation bond on May 26, 2026, with a request that DEQ apply the bond funds to the proposed exploration project if the amendment was approved. DEQ accepted the bond on June 3, 2026, and issued an Approval to Proceed for the project on Friday, June 5, 2026. The Exploration License Amendment authorizes collection of subsurface geological information through core drilling to characterize mineralization at the Columbia Gold Project area, building on prior exploration conducted in 2016.
The exploration activities are authorized to take place near Lincoln, with up to 1.53 acres of surface disturbance on ground previously disturbed by exploration activities. Proposed surface drilling is authorized to total up to 14,359 feet in drill holes, may reach a maximum depth of 2,296 feet, and is anticipated to intersect the groundwater table. No new access roads are authorized to be constructed, but operations may include overland travel. Reclamation of the disturbance is required.
In the final EA, DEQ discloses potential environmental impacts from the project and DEQ’s determination that the proposed project meets the requirements of the Metal Mine Reclamation Act. The final EA is not a decision document but discloses potential impacts from the project.
Sentinel Metals posted a performance reclamation bond on May 26, 2026, with a request that DEQ apply the bond funds to the proposed exploration project if the amendment was approved. DEQ accepted the bond on June 3, 2026, and issued an Approval to Proceed for the project on Friday, June 5, 2026. The Exploration License Amendment authorizes collection of subsurface geological information through core drilling to characterize mineralization at the Columbia Gold Project area, building on prior exploration conducted in 2016.
The exploration activities are authorized to take place near Lincoln, with up to 1.53 acres of surface disturbance on ground previously disturbed by exploration activities. Proposed surface drilling is authorized to total up to 14,359 feet in drill holes, may reach a maximum depth of 2,296 feet, and is anticipated to intersect the groundwater table. No new access roads are authorized to be constructed, but operations may include overland travel. Reclamation of the disturbance is required.
In the final EA, DEQ discloses potential environmental impacts from the project and DEQ’s determination that the proposed project meets the requirements of the Metal Mine Reclamation Act. The final EA is not a decision document but discloses potential impacts from the project.
To view the Approval to Proceed and the final EA for the Columbia Gold Project, please visit the Hardrock Mining page on DEQ’s website.