Park at the Gravel Pit (Rainbow) trailhead east of Glen Haven on CR 43. You can also make your way up from downtown Glen Haven, but it's longer and requires a difficult bushwhack. DO NOT attempt this cache if you aren't comfortable climbing high rocks with precipitous drop offs, and don't climb them if they are wet. It's not safe.
The potholes in these rocks have been known as Bath Rock for almost a century. Harry Piper (of Piper Meadows fame) would ride his horse up here over a long-gone trail to take a cooling dip in the pools on a warm summer night.
Potholes are erosion pits that slowly widen and deepen with time. They commonly form in arid environments and are most often found in sandstone, but you can also find them in other silica-rich rocks such as granite and limestone. Although mechanical weathering plays a role in their formation, they contain a biofilm which is the main process by which the depressions expand. Cyanobacteria, fungi, and algae in the film break down siliceous minerals in the rock and suspends them in solution. When the pothole dries out, the fine debris left by this biological activity is carried away by the wind.
Any lifeforms living in a pothole must contend with rapid changes in temperature, pH, O2 and CO2 concentrations, and water content. If you come here in the summer, notice the small creatures that inhabit them, free from predation by larger animals like fish. Residents in this area have reported finding fairy shrimp in the pools.

Standing inside the largest bathtub
This cache is part of a geotrail of historical caches in the Glen Haven area. Retrieve the code from all 14 caches plus the found date of the virtual and receive a commemorative geocoin. The cache list can be found here: Historic Glen Haven GeoTrail. And remember not to be a cache pirate! If you take something, leave something at least as good for the next cacher.
Additional Waypoints
0166K9W - Gravel Pit TH
N 40° 27.427 W 105° 25.563