Rainbow is a very popular site.
Most visitors wear swimsuits, but skinny-dippers love it too.
After crossing the bridge, turn left and then make another sharp left. Park and walk upstream to Rainbow Pool. A little skinny-dipping happens at Rainbow, but more takes place upstream and downstream. For the best site, park near the blocked-off dirt road, walk down the road to Rainbow, and continue .7 miles, to the area where the south and middle forks come together. Unknown legal status, suited users predominate, hike to best spot is steep.