Colorado's southwesternmost city has perpetually verged on all that is desirable in the American Southwest for tourism, recreation, and high-desert living. Cortez is surrounded by scenic mountains and red-rock canyons, Anasazi archaeological sites and a varied Native American heritage, and a sunny climate. Yet for centuries, rugged landscapes and lack of water made communication, transportation, and commerce difficult. Residents developed a fierce self-reliance. Area farmers received a boost when the Dolores River was diverted in 1889 by the nearly unimaginable man-and-mule-hewn Great Cut and...