The Bureau of Land Management has acquired 285 acres of patented mining claims around Silverton as settlement in a lawsuit against a company that once operated the Mayflower Mill there. The agreement with Standard Metals Corp. consolidates BLM holdings in the Alpine Triangle and allows the agency to better protect cultural resources, wildlife habitat and viewsheds.

Peter Butler's late October tour of abandoned hardrock mines began high on Red Mountain Pass near Silverton, Colo., off a highway so narrow that, in places, its shoulder crumbles off cliffs. Butler, a water wonk with springy silver curls, is the co-coordinator of the Animas River Stakeholders Group, a local watershed group, which has been cleaning up abandoned mines for 18 years.

The Chino copper mine near Silver City, New Mexico is one of the longest-operating mines in the West. The mine’s current owner, Freeport-McMoRan, just started mining there again in 2011 and the company is on the hook to restore thousands of acres of heavy metal-contaminated groundwater.

A new federal policy should protect "good Samaritan" groups from liability if they try to stanch dangerous chemicals leaking from abandoned mining sites in the Colorado mountains and beyond, environmental officials say. The Denver Post reported Sunday that the Environmental Protection Agency tweaked its policy after years of prodding by Colorado Democratic Sen. Mark Udall.

There are about 7,300 abandoned hard-rock mines in Colorado and a large percentage of them now drain toxic substances.

Concentrations of metals in the upper Animas River and its main tributaries, Cement and Mineral creeks, pose problems for invertebrates, fish and the animals that prey on them, an Environmental Protection Agency study finds. The study is a draft, and the conclusions are conservative, the report says.

An award-winning study by the Colorado Geologic Survey has found that highly acidic surface water preceded mining activity by thousands, perhaps millions of years. The report was recently given an award by the Geological Society of America as the best environmental publication of 2011.

Building a treatment plant to remove heavy metals from abandoned mines along Cement Creek may cost $6.5 million, and operating it could cost another $910,000 a year, according to a Sunnyside Gold Corp. consultant. Sunnyside Gold Corp.