The Petroglyph Canyon Trail is the main reason most visitors come to Sloan Canyon. The route follows a narrow desert wash south from the trailhead into a basalt-walled canyon that holds an estimated 300 rock-art panels — bighorn sheep, hunters, geometric spirals, anthropomorphs, and shapes whose meanings are now opaque. The first carvings appear within the first kilometre of trail and they continue, scattered on boulders and walls, for several kilometres more.
The hike is around 7 km round-trip with modest elevation change but involves scrambling over a couple of large rock barriers in the wash. There is no shade, no water, and no cellular signal once you drop into the canyon. The trailhead is on a high-clearance dirt road accessible from the south end of Anthem — a passenger car may make it on a dry day but not after rain. Go in the cooler half of the year; midsummer afternoons here are dangerous.