When we got close to the park entrance on MI 123 our GPS wanted us to go another.5 mile to the campground(CG) but a trailer was turning into a state park road so we followed. Good choice as this was the correct road that led to the gate where you register and checked in. The road the GPS was taking us to is currently only used as an exit from the CG. After a not-so-informative check-in, we headed into the park to find water. From the online map, we believed there was a water spigot near our site so we drove to the site only to find it was not a water hose assessable spigot. Then we headed to the dump station where we did find two potable water spigots on each side of the dump station. There was a permanently fixed hose coming out of the spigots, but the first one’s threads were worn out and wouldn’t stay screwed in. We had to wait for another rig to get fresh water and dump before we could move forward to the second one that did screw in so we could fill our fresh water tank. After that, we headed to site 110 that’s an easy back-in but only electric(50 AMP/30/20). The 100s loop is newer and it's big rig friendly with sites nicely spaced apart. Site 110 is probably the most spacious and private site in the CG as it sits in a little berm. Site 112 is nicely spaced, but you will get highway noise. Concerning RV sites in the main CG area, there is a separate tent-only area on the lake, and RV sites closest to the lake tend to be smaller in site length but we saw a couple of 36 to 40-foot 5th wheels with the tow vehicle parked wherever. In the 20 to 40 numbered sites that are not on the lake, we noticed larger class As and a couple of toy haulers. In the mid-30s sites across from the lakeside, large rigs were parked willy-nilly to make their rig fit. All the original sites are pretty much crammed in together but if you want to be where all the action is i.e. partiers and kids, this would be your area. When you get past site 40 there are 90-degree back-in sites of various lengths with most having a lot of trees and vegetation between sites giving more privacy. The 35ish-foot 5th wheels we saw in there, didn’t seem to care about tree branches scraping the roof. One note about the 41- 60s area is that the power boxes are behind every two sites and shared. Depending on how you are positioned on the pad, and where the power cord connects to the rig, you may need about 60’ of power cord to reach the power box. We also noticed on our walks around the CG that due to the poor to nonexistent cell signal here(1 bar on Verizon), people especially teenagers were sitting around talking to each other versus staring at phones. There were plenty of nearby trails to explore with the dogs, including a dog beach. McLain makes a great staging point to explore the area and take in Eagle River and Copper Bay attractions.