SACRAMENTO, Calif. (AP) — Across the West, early miners digging for gold, silver and copper had no idea that one day something else very valuable would be buried in the piles of dirt and rocks they tossed aside.

There's a rush in the U.S. to find key components of cellphones, televisions, weapons systems, wind turbines, MRI machines and the regenerative brakes in hybrid cars, and old mine tailings piles just might be the answer. They may contain a group of versatile minerals the periodic table called rare earth elements.

"Uncle Sam could be sitting on a gold mine," said Larry Meinert, director of the mineral resource program for the U.S. Geological Survey in Reston, Va.

The USGS and Department of Energy are on a nationwide scramble for deposits of the elements that make magnets lighter, bring balanced hues to fluorescent lighting and color to the touch screens of smartphones in order to break the Chinese stranglehold on those supplies.