What are the Sierra Bathtubs (also known by several other names, including Indian Bathtubs)?

Are these naturally formed holes in the relatively solid granite (this one partially filled with mud and rainwater), or were they created by the conscious efforts of American Indians? And if they were created by humans, to what purpose? The answers are not known. We do know the bathtubs seem to be associated with Sequoia groves and often enough seem to set in a more or less straight line. This is one of perhaps a dozen found on the western edge of Mountain Home, and other bathtubs are scattered around the southern Sierra Nevada Mountains.

We also know humans seasonally inhabited this portion of the Sierra Nevada, in a place we today call Sunset Point, for several thousand years. These people largely disappeared from this region of the Sierra Nevada a few years after the 1848 Gold Rush brought thousands of immigrants into Califoria.