Great Park!
Our stay at Osage Hills was excellent. The showers and facilities were clean, the staff was friendly, and the trails were nice. We camped near the lookout hill which had a little bit of traffic, but not intrusive. We went in early fall and found a few scorpions - one in my shoe! So be on the lookout.
There are a few different trails, all well marked. Even though we didn't get out on the water, there was access and a nice lake. There is a shallow area with a few small 'rapids' where kids can play and explore. All in all, a really excellent campground. We plan on this being the campground we take our friends with kids to as there is lots to do, amenities are nice, and trails easy to navigate.