The Details

This is MM's own map of the area covered by their claims and permits.

It is part of the FAQ on their website. You can download the PDF file here. Feel free to take it with a grain a salt.

Note that this area includes most of the west block of the range including Mount Moss and falling just shy of Lavender and Hesperus, essentially endangering almost all of the highest peaks.

First, a brief summary:

Metallic Minerals Corp, a Canadian prospecting company, with investment from Newmont Corp has been drilling exploratory core holes near Bedrock Creek in La Plata Canyon on the patented mining claim known as the Allard mine. They have identified 16 other sites to investigate according to investor presentations. The company press releases are very optimistic about ore quality and ore body size.

The prospecting permit requirements do not take into account the much greater impacts to the area and environment that would occur if the activity progresses to mining and the permitting process has gone largely under the radar of the public. The impacts on the La Plata Canyons' river habitat, downstream water quality and other public uses are potentially very significant, particularly if the activities progress to industrial scale mining.

Porphyry Copper deposits are typically mined with an open pit but Metallic Minerals suggests that it would be mined with an underground technique called block caving which is highly automated and would be highly destructive to the area above the mine (see below).

Recent developments:

Based on recent news releases and information disseminated at Metallic Minerals recent open houses it appears that more core holes will be drilled in 2026 or early 2027 on Copper Hill and/or in Rush Basin, and possibly additional holes near the Allard site.

It appears that core hole drilling was delayed due to a lack of funds and Metallic Minerals needing to modify their Plan of Operations with the USFS.

During the summer of 2025 Metallic Minerals raised approximately $8M CA to further the La Plata Project (see news release links below).

Again, based on information from recent open houses, they intend to use the newly raised millions to revise their Plan of Operations with the USFS. A previous amendment to the original Plan of Operations (approved by the forest service in January 2023 under a Categorical Exclusion) was rescinded this past May presumably due to the amendment not being sufficient to meet their needs and the one year limit on a Categorical Exclusion making it difficult to accomplish the drilling they want to do.

Stay tuned for opportunities to comment on the likely forthcoming new Plan of Operations with the USFS that may trigger an EA under NEPA rules (although in the current political environment, it is unclear what NEPA rules are being followed).

Other key information from the open houses includes their plans to construct a pond in Rush Basin for drilling water needs and that the Substitute Water Supply Plans approved by the Colorado Department of Water Resources will likely go unused.

Block Cave Mining

As noted above, MM has concluded that this method of mining is the only practical possibility in the La Platas. Googling this will produce numerous presentations and descriptions of this rarely used method.

It is sometimes touted as a more friendly alternative to strip mining, because it uses an underground mining technique. Do not be fooled.

An absolutely inevitable result of this technique is subsidence of the land above the mine. One such mine exists right here in Colorado - the Henderson molybdenum mine near the small town of Empire. The mine was constructed underneath Red Mountain. Because the mine was started in the 1970s, and major subsidence began in 1980, I was unable to find a "before" photograph (haven't given up yet), but this is what it looks like today:

Photo from 1989 (Wikipedia)

Note in the satellite photo that a small lake has formed and consider this report concerning the Pebble Mine in Alaska. Lakes in subsidence pits inevitably become sources of toxic water pollution.

Current satellite photo (CalTopo)

In the news:

Fortunately, local coverage of this project is picking up. (Note that information in the older articles is often wrong as developments have moved rapidly.)

The Durango Herald:

The Telegraph:

KSUT:

10/29/24: Is mining coming to the La Plata Mountains?

And from the world of finance (there's a lot of these - here's a few examples):

Links into the Metallic Minerals Website

If you check out their main web site, you'll see that they are involved in other projects, primarily in the Yukon territory. You'll also see they are prominently advertising their work in the La Platas.

This is the section dedicated to the La Plata project. You'll find links to technical reports on the geology and drilling results in here.
A subsection of this is what they call the "Community Website". This is clearly aimed at the public (as in "public relations").
Of some particular interest is this presentation directed at investors.

Newmont Corporation

And here is an article concercing MM's main investor.