Ribbon of Life: The Importance of Free-Flowing Rivers to Wildlife Conservation in the Southwest U.S.

The Southwestern United States is a landscape largely defined by water. The canyons, ridges, mountains, and playas of the Chihuahuan, Mojave, and Sonoran deserts, as well as the Colorado Plateau, have been carved by two great river systems, the Colorado River and the Rio Grande. The resulting habitat supports a wide diversity of fish and wildlife species, from the megafauna of alpine valleys and high mesas to the native fish, avian, and aquatic riparian species of deep desert streams and gorges. Rivers have an outsized importance for wildlife everywhere, but in the arid regions of Arizona, Colorado, New Mexico, and Utah, they are even more critical to the maintenance of biodiversity.