Beautiful
Remember that you're at elevation so it can get cold at night even in the summer. Twin Lakes and all of the surrounding Mammoth area is gorgeous. You'll have plenty of hikes to choose from, go fishing, or hit the slopes (biking during the summer and snowsports in the winter).
Cell service for ATT wasn't very strong so take some time away from the rest of the world. You can run into town for reception and wifi if needed.