Hidden in the high desert between Pine and Camp Verde, Fossil Creek is one of Arizona's two federally designated Wild and Scenic rivers — a spring-fed, travertine-blue oasis that pours some 20,000 gallons a minute out of the ground and brings its canyon vividly to life. Along its course lie several beloved swimming and hiking destinations, including two waterfalls; this one, the “Toilet Bowl,” is the swimming hole at the old Fossil Creek dam.

Despite the unglamorous nickname, it's a gorgeous spot. The name comes from a round, natural chute on the side of the river: jump or slide in and the swirling water spins you around the “bowl” before flushing you out into the deep main pool at the base of the falls. There's even a shallow cave beside the pool where swimmers duck out of the desert sun. It's a favorite with cliff-jumpers and swimmers, though water levels and submerged hazards change from year to year, so it's always worth checking the depth and conditions carefully before you leap.

The dam is reached by hiking in on the Flume Trail from the west or the Fossil Springs Trail from the east. Come prepared either way: the trails are hot and exposed, and the climb back out — especially via Fossil Springs — is long and strenuous, gaining well over a thousand feet in the desert heat. Carry far more water than you think you'll need, and remember that the creek water is not safe to drink without purification.

A permit is required to visit from April 1 through October 1, and the Coconino National Forest enforces it strictly. Each permit covers one vehicle at a designated lot and is reserved in advance through Recreation.gov; group size is capped (currently 12 people), drivers must reach the access point by early afternoon (the entry gate closes at 3 p.m.), and there is no camping within the permit area during the season. Book ahead, because permits for this popular spot go fast. Outside the permit season no permit is needed, but the access roads and weather can be far less forgiving.

The dam is a relic of history. For most of the twentieth century, Fossil Creek's water was diverted through a flume to a small hydroelectric plant — one of Arizona's first — leaving the creek bed nearly dry. In 2005 the dam was decommissioned and the springs' full flow was returned to the channel; the creek's travertine pools and lush greenery came roaring back to life, in one of the West's great river-restoration stories.

Plan for a full desert day: sturdy shoes, sun protection, plenty of food and water, and a dry bag for valuables. Be especially careful of the heat in summer, when midday temperatures in the canyon can be genuinely dangerous, and pack out every bit of trash to protect this fragile, precious oasis. With a permit in hand and an early start, the Toilet Bowl rewards you with one of the most memorable swimming holes in all of Arizona.