We love going to Prineville Reservoir State Park because it isn't too big- lots of grassy spaces, great boating and beach area. The swim area is marked and dogs are not allowed in that area so you don't have to worry about dog messes where your kiddos are walking barefoot and swimming. The campsites aren't very big but they have a nice layout that makes you feel like you have your own space. The restrooms are nice with showers available as well.