Mine Expansion Proposals, 2019 and 2026
and the U.S. Bureau of Land Management’s Determination of Common Variety (DCV) report
The New 2026 Mine Expansion Proposal: 56 acres
Rocky Mountain Industrials submitted a new mine expansion proposal the the U.S. Bureau of Land Management (BLM) on May 29, 2026.
Expansion of the permitted 15.7-acre quarry to 56 acres.
Request for a mineral materials sales contract to sell common variety limestone
BLM accepted the proposal as complete on June 26, 2026. Earlier versions of the expansion proposal submitted in January and December of 2025 were sent back to RMI as incomplete.
The proposal document has not yet been made public. BLM is conducting a technical review to evaluate impacts on other resources. Once the technical review is complete, BLM will begin a public review process.
The 2024 Determination of Common Variety report (DCV) and the 2025 Interior Decision
In response to the 2019 Rocky Mountain Industrials (RMI) mine expansion proposal, the U.S. Bureau of Land Management began a detailed mineral examination of the limestone resource.
This study is called a Determination of Common Variety (DCV). It evaluated the mine expansion and operations at the existing quarry by two factors:
Chemical composition of the limestone
End use of the limestone
It separated the sales of “locatable” limestone, which qualify for various protections under the Mining Act of 1872, from sales of “common variety” limestone,which are instead governed by the Mineral Materials Act of 1947.
After five years of work, BLM released the DCV report on Jan. 25, 2025. A U.S. Department of Interior Decision followed on Jan. 3, 2025.
The Original 2019 Mine Expansion Proposal: 447 acres
In 2018, Rocky Mountain Industrials (RMI) announced plans to vastly expand the limestone quarry, located on public lands directly north of Glenwood Springs.
Key elements of the mine expansion proposal
• Expansion of the permitted 15.7-acre quarry to a 321-acre mine and total permit area of 447 acres.
• Blasting and crushing 5 million tons of rock per year.
• Operations seven days a week, year-round for 20-plus years.
• Hauling truckloads of rock down Transfer Trail, across Highway 6 to Devereux Road, and across the Devereux Bridge to the rail yard area. The proposed rate of mining would result in up to 450 round trips per day.
• Ship the limestone across the Continental Divide to its rail load-out facility east of Aurora.
In November 2019, the U.S. Bureau of Land Management accepted RMI’s third version of the proposal and began taking steps to evaluate the proposal.
