Rising out of California's Mojave Desert are the Bristol Mountains, nearly 4,000 feet of rock blocking easy passage through the scorching desert. For decades, Route 66 and the Santa Fe Railway have had to bend south, acquiescing to the mountains' height. But in the 1960s, at the peak of atomic age, we had a plan to blast through the mountains once and for all—with nuclear bombs, of course.

It began with the Santa Fe Railway Company, which wanted a straighter and flatter path through the Bristol Mountains. The new route would require either a 2-mile long tunnel or cuts 500 feet deep into the mountain—far too expensive for railroad on its own. It did, however, pique the interest of the Atomic Energy Commission, which was searching for peacetime uses for nukes.

At the same time, California was building Interstate 40, a faster, smoother highway to replace Route 66. Wouldn't the California State Division of Highways also be interested in a straight shot through the Bristol Mountains as well? Thus, Project Carryall was born...