The loop trail through Estes Canyon and Bull Pasture is a must see when visiting Organ Pipe Cactus National Monument. The national monument is known for the wide variety of cacti species that grow here including the Organ Pipe cactus for which the monument is named. This scenic trail climbs into the Ajo Mountains through Estes Canyon up to a ridge above Bull Pasture where hikers can enjoy impressive views of the basin and surrounding areas below. The trail then continues back to the trailhead via Bull Pasture trail. There are some steep climbs along the trail and it can be very hot so bring plenty of water and avoid hiking the trail in the heat of the summer.