Mammoth Lakes Basin is located in the Eastern Sierras of California. You can drive through the lower basin around a series of lakes or you can get out there and hike to the more secluded upper basin lakes. This particular hike goes up to Crystal Lake near that granite crag to the right of center in the photo, which happens to be named Crystal Crag. The trail continues on up to the Mammoth Crest which is seen in the far background. There are even more lakes up over the crest.