Several unsuccessful early attempts were made to mine the nitrogen-rich guano deposit within the cave for fertilizer.
Based on a reputable mining engineer's estimate that the cave contained 100,000 tons of guano, the company constructed an elaborate plan to extract it.
A small airstrip was built on a nearby sandbar in the Colorado River, and all supplies and machinery needed were flown in.
The mining engineer's estimate of the potential size of the guano deposit proved wildly optimistic: the cave contained only about 1,000 tons of minable material.
Paleontologist Paul S. Martin and a colleague visited the mine in 1958, after reading a report in the New York Times that mentioned the guano came from "giant, meat-eating bats millions of years ago."
Martin collected a sample from 7 ft (2m) below the surface of the guano, which yielded a radiocarbon date of 12,900 ± 1,500 years ago.
As of 2007, some remnants of the old operation remain at Bat Cave,[3] and on the West Rim in the Hualapai Indian Reservation.