Was there a glacier here recently - you can see a "tide mark" in the black algae on the mountains behind that makes me think the snow was much higher quite recently. I've seen similar in the purcell's.
Yes; This area was originally covered by the Snow Creek Glacier. It has receded and opened up this basin in the last 100 years.
That's Witches Tower right of center. It has a couple climbing routes on it.