Rainbow Pool

Rainbow Pool is a wide green pool below a short waterfall on the South Fork of the Tuolumne River, a few miles east of Groveland on Highway 120. What makes it famous is how little effort it takes: the day-use area is right off the highway, and the water is a two-minute walk from where you park.

From Arnold it is a long day trip rather than an afternoon — roughly two and a half hours each way, down Highway 4 and around through Sonora and Groveland. Worth it if you are already heading toward the Highway 120 gate; a stretch if swimming is the only reason for the drive.

The falls drop maybe fifteen feet over a granite lip into a pool deep enough that people have been jumping into it for a century. Slabs on either side work as sunbathing rock, and the shade comes from oaks and pines on the canyon walls. Below the pool the river runs shallow over cobbles, which is where smaller children usually end up.

The water is snowmelt and it stays genuinely cold well into summer. In June it can be strong enough that the pool is not a place to swim at all; by August it is a calm swimming hole with a trickle of a waterfall at the top.

Follow Highway 120 east out of Groveland and the day-use pullout appears on the right where the highway meets the river. It is a small area and it fills on hot summer weekends, especially in the middle of the day. Early morning and late afternoon are quieter, and mid-week in September is close to empty.

Facilities are minimal — expect a vault toilet at best and no drinking water. Pack out everything, including food scraps, and skip glass entirely. Access, fees and whether the area is open at all can change between seasons; the Stanislaus National Forest posts the current status for Highway 120 corridor day-use sites.