In the 1930s Earl Dorr swore in a recorded affidavit that beneath Kokoweef Peak he had walked miles of caverns above an underground river whose black sands ran thick with placer gold, then dynamited the entrance shut to keep it. Miners have hunted a way back in for ninety years, and workings at the peak have chased the story within living memory.
Kokoweef Peak, eastern Mojave (San Bernardino County)
See it on the map
No single published account; the story is carried locally.