The 4 U.S. Deserts (Chihuahuan, Sonoran, Mojave, and Great Basin). These springtime images are from the 6 National Parks (Big Bend, Guadalupe Mountains, Carlsbad Caverns, Saguaro, Joshua Tree, and Death Valley) all geographically contained within our 4 U.S. desert boundaries (as of 2008). The Chihuahuan Desert occupies Texas, west of the Pecos River, the valleys and basins of central and southern New Mexico, and southeastern Arizona. The 3 parks in the Chihuahuan desert are: 1. Big Bend (1944) - located in western Texas, it is a diverse natural area of desert, mountains, and river – a land of extremes: hot and cold, wet and dry, high and low. The Rio Grande River provides the border with Mexico and in the heart of park lies the Chisos Mountains. Although only 2% of the park is woodland, it boasts more types of birds, bats, and cacti than any other national park in the United States. 2. Guadalupe Mountains (1966) - this park located in Texas, preserves an ancient (250 million years ago) marine fossil reef. This is a rugged mountain range, with deep, sheer-sided canyons, steep slopes, high ridges, and limited but dependable seeps and springs. Guadalupe Peak (the highest elevation) in Texas, is located in the park. 3. Carlsbad Caverns (1930) - also a UNESCO World Heritage Site (1995). This park located in New Mexico, and within the Guadalupe Mountains, is noted for its 750 ft. deep cave formed by sulfuric acid etching away at the limestone. --- The 2 parks located in the Sonoran Desert are: 1. Saguaro (1994) - located in Arizona, and named after the largest cacti in the U.S. 2. Joshua Tree (1994) - located in southestern California and named after this tree size indigenous yucca plant found here. This park brings three cosystems: Senora Desert – Mojave Desert – Little San Bernardino Mountains all together. --- The park located in the Mohave Desert is: Death Valley (1994) - located in southeastern California, and provides colorful badlands, snow-covered peaks, sand dunes, rugged canyons, and the hottest, driest and lowest spot in North America.