The Barrier Canyon Style here consists of larger than life size anthropomorphic (manlike) forms. The identifying characteristic of these figures is hollowed eyes or missing eyes, the frequent absence of arms and legs, and the anthropomorphs with bug-eyes, antennae, earrings, snakes in hand, and leg-less torsos. The "ghost-like" images, may represent shamanistic art associated with ritual activities of the Archaic people.

Source: Wikipedia

There are three distinct styles in present in Sego Canyon which represent three separate cultures and time periods.
Barrier Canyon Petroglyphs (6000 B.C. - 100 B.C.)
Fremont Indian Petroglyphs (600 A.D. - 1250 A.D.)
Ute Indian Petroglyphs (1300 A.D. - 1880 A.D.)