Just down the street from Starved Rock State Park and Matthiessen State Park is the much smaller(and less crowded) Buffalo Rock State Park. It has some trails, camping, a playground and other facilities, and is right next to the I& M Canal Tow Path.
At a leisurely pace, it only took me a couple of hours to walk all the trails. They are nice well-kept trails. Most of the surface is gravel but some parts are just dirt. The trail is wide and mowed at least two feet on either side. I’m not sure if bikes are allowed; I did see bike tracks and did not see any sign that indicated they were not allowed. Very little elevation changes and none that were steep. There are a couple of overlooks that offer beautiful views of Illinois River.
The campsites are directly off of the towpath. The furthest site(the group site) is three miles from the ranger station. There are four sites total. One of the sites is kinda small but big enough for a single tent and two campers. The largest site is the group site which is the only site with a picnic table and shelter. The shelter needed some work but overall was in decent condition. It as a fireplace that was pretty neat. Each site has a fire ring with grill. I did feel a little exposed being right off the trail. I was nervous leaving all my gear behind when I went for a hike. Nobody messed with my stuff though and everyone I saw was very friendly. I did have a visitor around two in the morning my second night. He was looking for a place to rest for a few hours and left at daybreak. The sites are only accessible by walking or biking.
The park has a playground, restroom(with running water), and drinking fountains with spouts. The water tasted funny but it was nice having a source to refill my bottles. Also, there are buffalo and that’s pretty cool.