During the Cold War, prospectors abandoned thousands of uranium mines, creating potential health hazards and an expensive cleanup.

U.S. Sen. Mark Kelly of Arizona has introduced bipartisan legislation to help expedite that cleanup.

The federal government estimates the industry left behind more than 500 uranium mines on the Navajo Nation and that there are at least 140,000 orphaned hard rock mines nationwide.

The sites pose threats such as erosion, chemical leaks and water contamination.

Kelly, a Democrat, and Republican Sen. Cynthia Lummis of Wyoming have introduced the Legacy Mine Cleanup Act, which bill aims to cut red tape and help coordinate agencies that work on the cleanup.