Sonoran Desert
The LCRV extends about from Hoover Dam to the Colorado River Delta. The Sonoran Desert itself is more than twice as extensive north-to-south, and about in width. Two species, Desert Ironwood-("Olneya tesota") and the Lesser Long-nosed Bat, have geographic ranges identical to the Sonoran Desert, and are indicator species of the "Sonoran Desert region". The spring flowering of ironwood, and the bat species migration arrivals also become indicators of annual or multi-year climate trends for regions of the Sonoran Desert.