- Located in western Pima County in the Sonoran Desert, on the Arizona-Mexico border
- Established in 1937
- Only place in the United States where the organ pipe cactus grows wild
- The monument's elevations range from about 980 feet to over 4,800 feet at the summit of Mount Ajo, the highest peak in the park
- Home to many animals, including desert bighorn sheep, mule deer, javelinas, mountain lions, gray foxes, coyotes, desert tortoises, Gila monsters, tarantulas, scorpions, and a variety of lizards and snakes