There is a fine bouldering wall that is about 20 feet high adjacent to the Twin Valley Campground in the center of the park. The wall is probably 150 long with a good variety of features. There is also potential for a very long traverse problem that could take a while to master. This would be an ideal place to boulder if you were camping in the campground, but be respectful of campers since this wall is adjacent to a handful of sites.
Go to the Twin Valley Campground near the center of the park. The bouldering wall is just south of campsites 262, 263, and 264.
A.C. - I was giving you time to look at your post and figure it out for yourself. ;-) The location on the post says "Twin Valley Campground Bouldering at Gov. Dodge State Park".I haven't boulder in that specific area but have done some bouldering and climbing in the Park. I have found some very good and solid sandstone. Tons of fun. Happy bouldering!