Bear Valley is a ski area located near Angels Camp, on highway 4, between Lake Tahoe and Yosemite, approximately 3 hours southeast of Sacramento, California, USA.
Near Bear Valley lies Ebbetts Pass, which has one of the best known caverns, Mercer Caverns. It is located 1 mi/1.6 km north of Murphys, on Sheep Ranch Road. The cave was originally used by the Indians as mortuary cave, but later was abandoned and its entrance was covered with debris, until pioneers discovered it in 1885.
Inside there are crystal formations, such as Angel Wings and susceptible compositions of aragonite, along with stalagmites, stalactites and also a labyrinth of underground, that visitors drawn for centuries. The tours in the cave include Fairies Grotto, Oregon Loft and Gothic Chamber. The tour lasts about 45 minutes and is a quarter of a mile long. You won’t cover all the distance at once.
There are several stops, where the guide will explain the history and geology of the cave and give you time to take some pictures. There are no tripods or video cameras allowed. The tour has totally 440 steps, 208 down into the cavern and 232 up out of the caverns.
You should be careful on some of the steps, because they are steep and narrow. The tour is moderately strenuous, mainly on the way out, but there is no crawling. The main temperature is constantly at 55 ºF/12.8 ºC with 90% humidity.