The Plowshare Program — the U.S. government's effort to find peaceful uses for nuclear explosives — had proposed using atomic bombs to dig canals, create harbors, and excavate mountain passes since the late 1950s. The physics was sound in a narrow sense: nuclear explosions do move enormous quantities of earth. Project Carryall applied this logic to a specific engineering problem: how to route a highway and a railroad through the Bristol Mountains in the eastern Mojave Desert.

The conventional alternative was expensive and time-consuming. Nuclear excavation, by the AEC's calculations, would be faster and potentially cheaper. The 23 devices — 22 nuclear plus one for crater formation — would create a pass through the mountains that trains and vehicles could use. The Southern Pacific Railroad was a partner in the proposal, which explains why both a highway and a railroad figured in the plan.

The AEC's environmental assessment was, by modern standards, cavalier. The dust cloud from 23 nuclear detonations in the Mojave Desert would extend seven miles wide at surface level and travel up to 100 miles downwind, depending on wind conditions. A four-day closure of all human activity in the affected area was deemed sufficient precaution. The assessment also acknowledged the possibility of 'occasional rock missiles' reaching altitudes up to 4,000 feet — fragments of Bristol Mountain ejected by the blasts and following ballistic trajectories across the desert.

The fallout question was addressed through timing: detonations would be scheduled for periods when winds blew in favorable directions. 'Favorable' meant away from population centers, which in the eastern Mojave wasn't difficult — the area is among the least populated in California.

California withdrew its support from Project Carryall in 1966. The state's objections centered on the radiological and environmental risks that the AEC's optimistic framing had minimized. Three years later, in 1969, the Southern Pacific Railroad dropped its participation — the railroad had been the project's primary industrial sponsor, and without its support, the rationale for the specific route collapsed.

The highway through the Bristol Mountains was eventually built, conventionally, without nuclear assistance. The pass that Project Carryall proposed to excavate with 23 bombs was blasted and graded with conventional explosives and equipment over a longer period at greater cost. A historical marker in Ludlow commemorates the proposal — a monument to an idea that was technically plausible, briefly serious, and ultimately rejected.

Project Carryall was not unique in its ambitions. The Plowshare Program proposed nuclear excavation in Alaska, Nevada, and along the Panama Canal Zone. What distinguished Carryall was its ordinariness: it wasn't proposing to create something spectacular like a new harbor but simply to build a road pass through a relatively modest mountain range in the desert.

The Bristol Mountains, which Project Carryall would have reshaped, still stand. Amboy Crater's cinder cone rises to the west, a reminder that the Mojave has done its own explosive reshaping over geological time — less controlled, less documented, and on a scale that 23 nuclear devices wouldn't have approached. The desert has its own way of moving mountains.