We visited here last weekend. This is a great state park with lots of things to do. We hiked the entire perimeter of the lake, which took about three hours, which included a swim for the dog. This is the most visited Wisconsin state park, so get there early before the parking fills. We got there about 7:00AM and parked with no problem, by 10:00AM there was no parking left.
There is lots of RV and tent camping sites, but the only some of the RV sites have power and none, as far I we could tell, have water or sewer.
We saw many people swimming the length of the lake, paddle boarding, hiking, picnicking, sitting on the beach, and even saw a military indoctrination march of about 50 high school age kids.
There are hiking trails that go to the tops of the ridges on both the east and west side. They are pretty challenging and we decided to take the flat loop, given that is was so hot and humid.
The trail on the west side of the lake is in the state park and is pretty rough as it is a paved path through the boulder field at the base of the cliff.
The east side of the lake is a railroad right of way, that you're not supposed to walk on, but many do.
View looking south from the lodge
See the kayakers?
Map of the park
You know you're in Wisconsin when
Devil's Lake is a great park and we'll definitely go again.