The NMBGMR has been examining the environmental effects of mine waste rock piles throughout New Mexico since the early 1990s. There are tens of thousands of inactive or abandoned mine features in 274 mining districts in New Mexico (including coal, uranium, metals, and industrial minerals districts), however many of them have not been inventoried or prioritized for reclamation. The New Mexico Abandoned Mine Lands Bureau of the New Mexico Energy, Minerals and Natural Resources Department estimates that there are more than 15,000 abandoned mine features in the state. The U.S. Bureau of Land Management recently estimated that more than 10,000 mine features are on BLM lands in New Mexico and only 705 sites have been reclaimed. The U.S. Park Service has identified 71 mine features in 7 parks in New Mexico, of which 12 have been mitigated and 34 require mitigation. Additional sites have been reclaimed by the responsible companies and the Superfund program (CERCLA).
The New Mexico Bureau of Geology and Mineral Resources has collected published and unpublished data on the districts, mines, deposits, occurrences, and mills since it was created in 1927 and is slowly converting historical data into a relational database, the New Mexico Mines Database. More than 8,000 mines are recorded in the New Mexico Mines Database and more than 7,000 are inactive or abandoned. These mines often include two or more actual mine features.