In late spring, the San Juan charged like a desert bighorn ram in the rut. It was strewn with cottonwood seeds: The puffy globs drifted on the khaki surface like a monsoon over a desert escarpment.

Yuma sits at the crossroads of Arizona, California, and Mexico, making it a melting pot of cultures and flavors. The Colorado River flows right through town, creating an oasis in the desert that begs ...