Death Valley's Ancient Underground

S1, E1: On August 5, 1947 an astounding announcement was made: Dr. F. Bruce Russell, a retired physician from Cincinnati, had found a cave with giant mummified remains and artifacts from a lost civilization. Fifteen years earlier a miner broke through a mine shaft and into a tunnel of caverns, which he also said, led to the remains of an ancient people. And, before that, one of the men who worked on the wagons hauling borax stumbled up on a cavern with remnants of a forgotten and lost race. Every one of these accounts takes place in Death Valley which begs the question: Are there really caverns with hidden gold and ancient mummies in Death Valley?