Cross Mine Above Nederland - Comment by Wednesday April 2
Written by the BCAS Conservation Committee
Your voice is needed to comment on the proposed expansion of the Cross Mine from 10 acres to over 200 acres.
Members of the public can comment on the water quality impacts and certain other impacts of the proposed expansion of the operations of the Cross Mine above Nederland. Water from the Cross Mine flows through Coon Track Creek into groundwater and tributaries before entering Barker Reservoir, a significant source of drinking water for the City of Boulder.
State Senators Judy Amabile and Janice Marchman and State Reps. Junie Joseph and Leslie Smith wrote an op-ed in the Boulder Daily Camera expressing concerns about the potential effects upon both well water up-canyon and drinking water for Boulder City coming from Barker Reservoir. You can read the op-ed here
Cross Mine Vicinity Map
BACKGROUND
The owners of the Cross Mine, a high elevation gold and silver mine outside of Nederland abutting Roosevelt National Forest, filed an application for permission to expand its current 10 acre site to over 200 acres. With extensive underground tunneling, the applicant projects that the mine has the potential to produce 70,000 tons of gold, silver, zinc, and lead ore per year for 50 years. Each year, up to 40,000 cubic yards of waste rock may be removed.
This long-standing mine was purchased by Grand Island Resources (GIR) in 2017. Since that time, the mine was temporarily shuttered by a 2021 cease and desist order due to excessive releases of heavy metals, including copper, gold, silver, cadmium, zinc and lead, following an underground tunnel collapse. After GIR worked to repair and upgrade the water treatment system, the cease and desist order was lifted in 2023. GIR is now working through the process of obtaining permission for a much-expanded operation.
Despite GIR’s efforts to maintain acceptable water quality, there was a large, inadequately explained spike of copper released in December 2024. The regulatory standard for copper is just .2 mg/l, but the December 2024 measurement is 3.4 mg/l. This is documented in correspondence between the Colorado Division of Reclamation, Mining and Safety (DRMS) and GIR, Read DRMS’s letter to GIR here and GIR’s response here.
Additional history of the mine and its operations can be found in the following articles and links:
The Mountain-Ear March 20, 2025 “Nederland On Mines: Concerned, Not Opposed”
The Mountain-Ear March 13, 2025 "“Nederland Weighs Opposition to Mines Reopening”
The Mountain-Ear March 6, 2025 “Will Nederland’s Mines Reopen?”
The Mountain-Ear February 22, 2024 “Status of the Caribou and Cross Mines”
https://archives.boulderweekly.com/news/digging-for-the-truth/
NOTE: We thank The Mountain-Ear for complimentary copies of their articles and for their in-depth coverage of the Cross and Caribou Mines.
If you’ve got time for a deeper dive, read Colorado Parks and Wildlife (CPW) comments covering fencing, noxious weeds and native re-seeding, wildlife escape ramps, and lighting.
POINTS OF CONCERN
For those wishing to comment, the following are points of concern to ask DRMS to consider when determining whether to approve GIR’s pending application. Please consider including the points most relevant for you.
The December 2024 water quality violation for copper combined with the 2021 Cease and Desist Order are significant red flags. The repeated surface and ground water violations suggest that the water treatment system may not be adequate for active mining conditions. Require the applicant to demonstrate (1) the ability to sustain compliance with water quality standards at current activity levels before permitting a 20-fold expansion; and (2) the ability of the upgraded water treatment system to effectively treat water from a greatly expanded operation of over 200 acres. Rigorously assess the likely impact of the proposed expansion of existing tunnels and the creation of new tunnels upon ground and well water.
50 years of mining is a long time. To ensure that the quality of downstream water complies with all applicable standards protecting humans, fish, and wildlife, put a rigorous and frequent water quality monitoring system in place for 100+ years. Also, if the applicant is to remove up to 40,000 cubic yards of waste rock for 50 years, then measures to prevent acid mine runoff, including testing of waste and host rock, are appropriate.
Ensure that the environmental protection plan addresses the adjoining area as well as points downstream; specifies which minerals and chemicals will be present in the ponds and at what anticipated concentrations; and explains how birds, aquatic, and land-based native wildlife will be protected. Additionally, the applicant plans to re-route surface water flows uphill of the operation around the disturbance area. Again, require the applicant to explain how Coon Track Creek, its associated wetlands, and the surrounding ecosystem will be impacted by this re-routing and how they will mitigate the impact.
Require the maximum permissible financial warranty to cover the risk of bankruptcy and all potential environmental damage so that local municipalities and downstream water users are buffered from potential clean-up and water replacement costs to the maximum extent permissible by law.
Living as we do in a landscape that is fire adapted, but also fire prone due to fire suppression, require that applicant explain how explosives will be stored and used so that the fire danger is reduced to the absolute minimum possible. Then consult with experts, including the US Forest Service, about the adequacy of these measures.
It is critical to take all necessary measures to prevent this site from becoming another Superfund site, including seeking comprehensive, independent studies of critical aspects of the proposed mining activities.
HOW CAN I COMMENT?
Comments can be submitted to the Division of Reclamation, Mining and Safety through Wednesday, April 2 using this link or by clicking the blue button below. Be sure to reference Permit # M1977410 in the box labeled Permit Number and check “new permit” just above it. The county, site name, and permittee/operator name are Boulder, Cross Gold Mine, and Grand Island Resources LLC. You will be given a choice at the top between filing an objection (which is an expression of disapproval), offering approval, or making a general comment, which is described as an observation or general feedback. Written comments can also be mailed to the DRMS, 1313 Sherman St, Room 215, Denver, CO 80203. Be sure to reference Permit # M1977410.
Thank you for your support of local conservation issues,
Boulder County Audubon Society Board of Directors & Conservation Committee
Caribou Townsite, in the vicinity of the Cross Mine. Photo courtesy of Glenn Cushman.