This deservedly popular trail crosses Oak Creek several times as it winds through the ponderosa and the canyon, where walls soar more than 200ft in some places. The trail is marked for the first 3 miles, but you can scramble along the stream bed for the 14-mile length of the canyon.
Most people head straight into the canyon, but if you cut over to the creek within the first 50ft just beyond the parking lot, you'll find a particularly nice, sunny stretch with a swimming hole and shallow waters for splashing. It's an excellent hike for fall colors. It's located 9.5 miles north of Sedona (a few miles north of Slide Rock State Park) and 17.5 miles south of Flagstaff on Hwy 89A; look for the signed parking lot.