The picture is deceiving. That rock is tilted, and on top of several large boulders, and may require a ladder or some rock climbing gear to get to. Best option we have is an aerial view. The petroglyphs probably won't be visible from Google Satellite View, so you might have to take the hard way and rent a plane or helicopter to fly over that area.
Detective Holmes wrote:
The prominent peak in the middle-top part of the image is Mt. Tom. Basin Mountain is not far away to its left.
That picture was taken facing west or maybe even southwest (the "sunrise" description and the morning light hitting the peaks confirm that). This puts you in the vicinity of Bishop, CA, a ~45 minute drive away from Mammoth.
The elevation of Mt. Tom is 13,652′. The elevation of Basin Mountain is 13,190′. The two peaks are around 3 miles apart, with Basin Mountain almost exactly 2.9 miles directly south of Mt. Tom.
Bishop, CA is at 4,150'. That area looks to be a bit higher, perhaps around 4,500' or so. No luck with GPS Coordinates on EXIF data so far, but we can probably triangulate the area based on the focal length and aperture of the images.