The sun had just appeared over the rim of the mountains. The air was crisp and smelled of mesquite. Carlos got out of his truck and rode the boom lift thirty feet up to the viaduct. Six lengths of rail had been craned in yesterday, now neatly stacked on a set of four-by-fours. A final course of rebar had been laid lattice fashion on top of the first pour, and Carlos worked his way through the iron grid to check the ties that secured each rod.