A Strange Ground of Mounds

Have you seen these hummocks on the eastern side of the Diablo Range in California? Are they tailings of some kind? Do you know anything else about them?

Catching light | Radiant clouds in Altamont

Caught: the sun having a lazy day in the summer sky. A pic with a Samsung Galaxy Note 4 The week before last as we driving through Interstate 580 (I-580)…