The 3.5-mile loop to Estes Canyon and Bull Pasture (an elevated plateau) is probably the most interesting of the small number of maintained paths in Organ Pipe Cactus National Monument – the route climbs high into the Ajo Mountains, passing numerous species of cacti and other desert plants, and a variety of landscapes. Views from the endpoint extend for over 20 miles across the flat Sonoyta Valley into Mexico, and for a similar distance west to the Puerto Blanco Mountains. With an elevation gain of 1,050 feet, the path is somewhat strenuous, particularly in midsummer when the temperature may exceed 110°F, though it can be done in a couple of hours or so hence an early morning start on even the hottest day should see relatively pleasant conditions.

President Franklin D. Roosevelt created Organ Pipe Cactus National Monument on April 13, 1937.

Organ Pipe Cactus National Monument was created as a way to preserve a representative area of the Sonoran Desert. The new monument was part of a movement in the National Parks to protect not just scenic wonders but also the ecological wonders of the country.

Organ Pipe Cactus National Monument is the site of cultural resources that reflect long, widespread and diverse occupations by American Indian, Mexican, and European groups. The intersection of these three cultures is significant archaeologically, geographically, and internationally. Evidence of these cultures still remains today, and as you explore the monument, one cannot help but imagine what life was like living in the Sonoran Desert.

The AllTrails website has a description and map of a hike at Bull Pasture.