The Chihuahuan Desert straddles the U.S.-Mexico border in the central and northern portions of the Mexican Plateau, bordered on the west by the extensive Sierra Madre Occidental range, and overlaying northern portions of the east range, the Sierra Madre Oriental. On the U.S. side it occupies the valleys and basins of central and southern New Mexico, Texas west of the Pecos River and southeastern Arizona. The Chihuahuan has an area of 139,769 sq miles, making it the third largest desert in the Western Hemisphere and the second largest in North America, after the Great Basin Desert.Above are drawings from the Texas Parks & Wildlife Department's BIG BEND REGION COLORING BOOK, which includes Big Bend Ranch State Park, the largest state park in Texas, with over 300,000 acres of Chihuahuan Desert wilderness and 66 miles of trail. Have at it.