Disturbed land restoration (DLR)

What are Abandoned Mineral Lands?

Abandoned mineral lands (known as AML) are one of many types of disturbed lands in the National Park System. AML sites are 1) underground and surface mines, 2) placer and dredge sites, and 3) oil, gas, and geothermal wells. Commodities mined at these sites ranged from soft rocks such as coal and sand/gravel to hard rock minerals such as gold, lead, and copper. Sites can contain waste rock (unprocessed rock), tailings (processed rock), abandoned roads, fuel storage tanks, drainage diversions, buildings such as mills and assay shops, deteriorating structures such as headframes and tramways, and abandoned heavy equipment.

View a photographic overview of AML in the National Park System

Abandoned mine opening in Wrangell-St. Elias NP&Pres

AML Inventory and Statistics in the National Park System

Abandoned mines are in 126 National Park System units. An ongoing inventory in the units so far revealed an estimated 3,100 sites with about 8,400 mine openings, piles of tailings, and hazardous structures and thousands of hectares of scarred lands.

National Park Service AML Program

The National Park Service has an on-going Abandoned Mineral Land Program and is an active participant with the broader inter-agency and national AML program associations.

Abandoned Mineral Lands Management Issues

Management of AML sites involves the following issues:

• Site Safety - Visitors can encounter a number of hazards at AML sites. The NPS has an active program to try to mitigate hazards and place warning signs at abandoned mine sites.
• AML sites can be the source of several environmental contaminants. The NPS tries to insure that environmental problems at the site are addressed.
• Preservation of historic features whether they are old buildings, old structures, prehistoric mining tools, or evidence of particularly remarkable engineering accomplishments. The NPS works closely with State Historic Preservation Officers to ensure that significant cutural values are preserved.
• Protection of habitat for threatened and endangered species. In many parks, abandoned mines are habitat for wildlife including bats, woodrats, and crustaceans. The NPS tries to insure that species are not impacted by either curious visitors or restoration efforts.

Examples of Abandoned Mineral Lands Projects

View brief summaries of AML projects completed in National Parks

Examples of Abandoned Mineral Lands Hazard Warning Signs

View a gallery of signs used on state and federal lands

NPS AML program sign catalog [page 1] [page 2] (c. 1992)

AML Technical Reports

• Handbook for the Remediation of Abandoned Mineral Lands
• Effective Management of Radiological Hazards at Abandoned Radioactive Mine and Mill Sites (pdf - 1.3 MB)
• Polyurethane Foam Applications in the Closure of Abandoned Mine Openings (pdf - 639K)
• Colorado School of Mines Report on Polyurethane Foam mine closures- (pdf - 666K)
• Abandoned Mine Safety Training Course Online - (pdf - 315K) (high resolution for print pdf - 1.7MB)
• Bat-Compatible Closures of Abandoned Underground Mines in National Park System Units (pdf - 897K) (high resolution for print pdf - 10MB)
• Bat-Compatible Closure Drawings (10 pdf files - 73 to 489K) 1a | 1b | 2 | 3a | 3b | 3c | 4a | 4b | 4c | 4d
• Safe Conduct of Bat Surveys in Abandoned Underground Mines (pdf - 48K)
• Job Hazard Analysis (pdf - 58K)