Interactive map shows abandoned gold, silver and uranium mines all over Maine

Yellow mine waste water is seen at the entrance to the Gold King Mine in San Juan County, Colorado, in this picture released by the Environmental Protection Agency (EPA) taken August 5, 2015. A contaminated plume of waste water accidentally released from a Colorado gold mine by U.S. environmental agency workers has spread downstream and reached northern New Mexico, officials said last month.

Yellow mine waste water is seen at the entrance to the Gold King Mine in San Juan County, Colorado, in this picture released by the Environmental Protection Agency (EPA) taken August 5, 2015.

SkyTruth is a West Virginia organization which, according to the Discovery Channel, uses “technology such as remote sensing and digital mapping to highlight environmental problems.”

In its latest project, SkyTruth used U.S. Geological Survey data to create an interactive map of all the abandoned mines in the country’s records, and ended up showing an enormous number of the potentially dangerous caverns scattered across America.

Overall, the map includes locations and basic information on about 65,000 sites the U.S. government has on the books as “past producers.”

While the interactive map doesn’t break its statistics down by state, it shows approximately 140 of the abandoned mines in Maine, including several for minerals the state isn’t widely known for, such as gold and uranium (the latter of which is used as a fuel source in nuclear power plants and some nuclear weapons).

SkyTruth’s interest in the subject is that America’s old mines can not only be structurally unstable, but that thousands harken back to an age when mining was unregulated. Open mines which were never properly cleaned up can become environmental problems, with a recent example being Colorado’s Gold King mine, an old work site left to fester and which has now polluted the nearby Animas River into a peculiar mustard orange color.

SkyTruth argues the 65,000 “past producers” on the country’s record books likely represent about 10 percent of all the abandoned mines actually out there, because prospectors for much of American history dug and vacated mines without keeping detailed records of them.

According to, which cites the state’s Department of Environmental Protection, there are actually about 700 open mines still in Maine, illustrating how potentially short the U.S. Geological Survey’s list really is.

Robert Marvinney, the Maine state geologist, said that number includes multiple openings for the same mining sites, however, and that only about 163 of those sites are metallic mines. The rest are quarries, like for granite, gemstones and feldspar, for example.

Marvinney said he reviewed the SkyTruth information and found that the organization included quarries in its interactive map as well.

He cautioned against lumping Maine’s abandoned mines in with the likes of the toxic gold mine polluting the river in Colorado.

Marvinney said that — aside from two well-known environmental cleanup sites, the Callahan Mine in Brooksville and the Second Pond-area copper mine in Blue Hill — the vacated mines in Maine are small and left little environmental footprint.

“We just didn’t want people to think that Maine was littered with these sites that look like what they have in Colorado,” he said. “We have 181 sites that had some kind of underground workings that are no longer active, and they’re almost all small. Most of these are just tiny things that were done more than 100 years ago. Most of them are shafts less than 50 feet deep and only a few are over 100 [feet deep].”

The federal government urges hikers and explorers to stay out of abandoned mines if they find them, noting there are myriad possible hazards, including unexpected dropoffs, toxic chemicals and low oxygen.

“I think the biggest hazard with some of these in Maine is that they’re pretty obscure,” Marvinney said. “It is possible to accidentally fall into them.”

To learn more about Maine’s mining history, click here.

Marvinney said interested readers can also research the state’s mines and mineral deposits on the state website.