• Sunset at Lake Mead's Boulder Basin

    Lake Mead

    National Recreation Area AZ,NV

Abandoned Mines Lands

Mine illustration

Abandoned mine land (AML) features represent a legacy of mineral extraction within the national parks. Management of these areas poses unique challenges since many abandoned mines are cultural resources that represent the history of local mining and also provide habitat for threatened and endangered species. Since many AML features are also hazards to public safety, several high-risk features at Lake Mead NRA have been mitigated by installing bat gates and cupolas, backfilling with existing waste rock or polyurethane foam, blasting entrances, or erecting signs and fences.

 
Abandoned Mines Lands (AML) Features
 
To date, at least 958 AML features have been documented within Lake Mead NRA. Of these, at least 175 and as many as 316 are considered to have hazards in need of mitigation.

Count Feature Description
168 adit Horizontal or near-horizontal entrances to underground mines
1 tunnel Horizontal openings that have two connecting entrances
184 shaft Vertical or near-vertical entrances to underground mines
13 inclined shaft Sloped entrances to underground mines
477 prospect Excavated mine features less than six feet deep; at Lake Mead NRA this term can apply to features with variable dimensions that are shallow test excavations
6 vent raise Vertical or near-vertical features excavated from underground to aid mine ventilation
21 structure Constructed feature such as head frame, building, foundation, etc.
88 other/unknown

 

Abandoned Mines & Public Safety


 

Abandoned mines are usually considered unsafe and should not be entered. Signs are posted near known mines to warn visitors to keep out. Since many AML features are hazards to public safety, several high-risk features at Lake Mead NRA have been mitigated by installing bat gates and cupolas, backfilling with existing waste rock or polyurethane foam, blasting entrances, or erecting signs and fences.

 
Covered-Mine-Final-Distant
Horizontal-Mine-Model-1
 
Polyfilled-Mine-Close-Up-Final
 

Mines as Habitat


 

Abandoned mines provide habitat for a number of wildlife species at Lake Mead NRA. One of the best-known animal residents is the bat, and many of the at least 19 species of bats found in the park are supported by abandoned mine features. These features can provide critical habitat to threatened and endangered species, particularly cave-adapted bat species facing declining natural habitat.

Historic Preservation


 

Many of the abandoned mine areas within Lake Mead NRA have been inventoried for cultural resources and have been documented as historic and archaeological sites. The majority of these abandoned mine features are related to hard rock mining operations. The Homestake Mine, near Laughlin, is the only abandoned mine site within the park that is listed on the National Register of Historic Places. Mining began at the Homestead Mine in the 1860s and was active until the 1930s. This site was listed on the Register in 1985 for its relationship to the history of mining in the area and its ability to provide information about a range of topics in mining history. Some of the abandoned mine areas that are considered eligible to the National Register of Historic Places include an unnamed mine near White Rock Canyon; the Empire Mine southwest of Lake Mohave; the Copper Mountain Group near Searchlight; and the Dupont Mine just north of the Copper Mountain Group.

 

Mine Density Map


 
Mine Density Map
 

Photo Gallery


 

References


 

National Park Service Geologic Resources Division http://www.nature.nps.gov/geology/aml/index.cfm

Nevada Abandoned Mine Lands Report to the Commission on Mineral Resources Nevada Division of Minerals, 2008.

Ninety-Sixth Annual Report for the Calendar Year 2007 Office of the Arizona State Mine Inspector, 2007. http://asmi.az.gov/userfiles/file/Annual%20Reports/2007AnnualReport_Final.pdf

Abandoned Mine Lands in the Department of the Interior (Final Audit Report) United States Department of the Interior, Office of the Inspector General, 2008.

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