This area requires a permit which you can buy at the ACE hardware in Nederland. However, after mid-September permits are no longer required or sold, as we found out when we arrived at the hardware store.
We camped about a mile down from Devil's Thumb lake because we got a late start (~4:00pm) and it started getting dark and cold. We made the hike into a two-day loop instead of out-and-back by summiting and then taking King's Lake trail back to the original trailhead. Beautiful sights all along this path! It's about 12-13 miles this way.
Plenty of access to water via various streams. Did not see many other people camping. Passed a few hikers the second day. Once you summit you can see the town of Fraser and also get cell phone service, but we did not have service in the valley before summiting. Note that it got quite cold this night in mid-September, just below freezing.
This is a backpacking trip. 12 mile out and back. This is part of the Indian peaks wilderness you must obtain a permit from the boulder forest service. Permits are 5 dollars for up to 14 days. This lake is amazingly beautiful. Lots of places to pitch a tent. The trail is not easy you work for it. But its all worth it when you get to the top. The directions are from the trailhead not directions to the lake. Arrive early to the trail head before 6:30am. Parking is hard during the summer but just get there early. This trail has water available along the entire trail. I only take a 1 liter bottle and filter all my water as needed.