Abandoned mine opening in Wrangell-St. AML Statistics in the National Park System Abandoned mines are in more than 140 of the 368 National Park System units. An ongoing inventory in the units so far revealed more than 2400 sites with about 10,000 mine openings, piles of tailings, and hazardous structures and thousands of hectares of scarred lands. In addition, there are 53 abandoned oil and gas wells in the National Parks that require permanent plugging and environmental assessment. As land managers, we have an affirmative duty to manage AML sites.
Visitors can encounter a number of hazards at AML sites.
We have to insure that environmental problems at the site are addressed. AML sites can be the source of several environmental contaminants. We want to preserve historic features whether they are old buildings, old structures, prehistoric mining tools, or evidence of particularly remarkable engineering accomplishments. We have to insure that threatened and endangered species that have chosen to make AML sites their homes are not impacted either by curious visitors or by restoration efforts. In many parks, abandoned mines are habitat for wildlife including bats, woodrats, and crustaceans.