A few weeks ago we went to another state park for a day hike. It's starting to be a thing. Go and see what each park has that warrants a park. O'Brian is a fine park if you want to go birding or maybe use a sight glass to find Beaver, Musk rats, and other critters but it's a little weak on adventure. I did see a lot of wild grasses, flowers, weeds, bugs.... so that's at least different and if your into Entomology it's crawling with bugs.
The open grassland is more like southern MN and Blue Mounds without the 4 hour drive. I'm behind on posting because I didn't know what to say and after some time realized that's the story. It's a fine park that's easy to get to and it has a little of everything but nothing grand like cliffs, waterfalls, or large lakes like our flagship parks. O'Brian gets by on being average and that's not an easy thing to do.
Scooby doesn't get people food but somehow know chicken is worth begging for.
They have 4 camper cabins but they are closed for the winter, just when they are most helpful.
This standing hollow tree is probably the best find of the day.
O'Brian is probably best used in winter for Cross Country with it's open space and flat terrain. Spring could be very wet and summer bugs beyond control. They don't allow winter camping so that really limits what you can get from the park. Your results may very.