It's 5:15 a.m. and dark when I drive over Raton Pass, the 7,835-foot-high saddle right at the boundary between Colorado and New Mexico. Animal crossing signs whiz by my window: first a clip-art bear, then an elk, then a deer. "Watch out" is an apt way to enter the state, particularly on this trip: New Mexico is the birthplace of the nuclear bomb and the site of its first test. That initial blast occurred southeast of Socorro, under the auspices of Los Alamos National Lab-led Manhattan Project.