The Horseshoe Canyon Unit was added to the park in 1971 in an attempt to preserve and protect the rock art found along much of its length.
[1][2][3] Human presence in Horseshoe Canyon has been dated as far back as 9000-7000 B.C., when Paleo-Indians hunted large mammals such as mastodons and mammoths across the southwest.
The gallery was a product of the Desert Archaic culture, a nomadic group of hunter-gatherers predating the Fremont and Ancestral Puebloans.
To see the rock art, visitors must descend 750 vertical feet (228 m) to the canyon bottom and hike approximately 3 miles (4.8 km).
The hike from the West Rim trailhead to the Great Gallery is roughly 6.5 miles (10.5 km) round trip, and requires 3 to 6 hours to complete.