There's a story on Mineweb.com that a U.S. Fish & Wildlife Service proposal to list the Sonoran desert tortoise [right, photo credit Tigerhawkvok on Wikipedia] as endangered would "limit livestock grazing, urban growth and development, mining and international border patrol activities in tortoise areas." As of 2003, there were 1096 active mining claims in the area of Arizona that would be affected.
Mineweb cites the FWS statement in the Federal Register that says,
"The petitioners state that mining activities (both small- and large-scale) adversely affect the Sonoran desert tortoise through habitat fragmentation, loss, and degradation; introduction of contaminants and fugitive dust (dust that cannot be attributed to a single point of origin, such as a smokestack); off-road travel associated with mining activities or roads created for said activities; and entrapment of tortoises in mine spoil heaps."FWS is carrying out a 12-month long study to determine if listing is warranted.