Yellowwood Lake is squarely in the middle of the Yellowwood State Forest. While a lot of Indiana is flat, the southern portion is most of Karst topography (rolling knobs varying from 400-1000 feet).
For camping, there is a car camp on the west side of the lake. I did not notice much traffic while I was there. It is possible to stealth camp on the east side of the lake, as well, but I didn't see any spots to camp along the shore. You can paddle there, but it's a small lake; only one mile long. However, if you're looking for paddle-camping options in Indiana, the best place by far is Lake Monroe, which is south of Yellowwood.