rexlion,
We've stayed one night at River Pines on the Ontonagon River about 6 years ago and it's fine but the sites are not large and side by side with hookups between. We only wanted electric so didn't check out the water or sewer. 2 couples with 2 TC's. Fairly level sites of dirt and grass with quite a few pine trees in the area. Not a very large CG and we did enjoy our stay. Actually not right on the river as it's across the River Rd from the river but close enough. Close to the nice little town of Ontonagon which is just across the new high bridge.
Very nice long sand beach on Lake Superior in the north part of town but the water is quite cool because it's Lake Superior which virtually never gets warm. Yes, it's between Copper Harbor and the Porkies but much closer to the Porkies.