We loved our time at Glacier!
Two families went so we reserved two sites next to one another. The sites were spacious - we were able to have 2 large tents in one site, and a Scamp trailer + screen tent in the other with plenty of space to walk around and hang hammocks. There were many little trails from our loop that brought you to Lake McDonald with amazing views. Overall it was a nice campground that was a perfect base for our many hikes that week.
I love this park and use it frequently for our "test runs". We have a new puppy and a new teardrop, so this was the perfect place for us to have our maiden voyage within 20min of our home. But besides just being close, it's also a really nice campground. It's very wooded and feels private. The RV section has sites that are a bit close together and open, but the tent sites (where we stayed) are much more secluded. The facilities are clean and well-kept.
The park itself is also really nice. There are lots of hiking trails, mountain biking, lake access for kayaking/paddle boarding… In the winter we love coming here for day trips to take advantage of the cross country skiing and snow shoe rentals.
It's a nice State Park close to the Twin Cities, right off the interstate (hence the name). We were really happy with our site (23) because it was the only one on the outer ring on that side of the campground, which gave us plenty of space and privacy. It was a big site, too, with a long driveway for our teardrop and a nice tent pad above the firepit/picnic table area.
The hiking itself was really nice with a couple of overlooks of the river. The glacial pothole section is really easy to walk and get to if you take advantage of the parking lot - probably good for families with young kids or those concerned about mobility. We opted for the hike from the campground. The campground is also close to the boat launch and kayak/canoe rentals for some nice water activities.
Note during this Covid season: The park sells firewood from the main office, but the office has limited hours because of Covid without a way to purchase a bundle when it's closed. There was a sign on the door directing you to the nearest gas station, but they were sold out by the time we stopped by. Odd to say since it's against the rules, but it may be worth planning ahead or to call to see when the office is open.
William O'Brien has two different campgrounds and we ended up staying at Savannah, and it was a really nice little campground. Most sites are relatively secluded, except mine which was kind of wide open and the location of a firewood drop box (74E). It was super large, though, so if there was a bigger party you could easily fit a few tents. The campground was really nice, but I'd probably pick a different site next time.
The hiking at the park was fantastic. We did one longer hike that had some surprisingly good views. It was hillier than I thought it would be - not a tough hike, but hillier in that you could experience some nice views. The second day we did the river side hike, which was also very pretty but was also much more popular. I'd recommend an early morning visit to that one, especially during these Covid times.
Unrelated to the park, if you forgot any supplies, the general store in Marine on St. Croix was adorable and had really good sandwiches. Like another review said, either way I'd recommend driving in from that way regardless - the winding road and the tree canopy is really pretty.
We stayed at Minneiska campground since Cedar Hills is under construction this year. It's a newer campground so the vegetation hasn't grown in fully yet - your neighbors are visible but there's good distance between sites so it wasn't a problem at all. The grounds themselves are really well-kept with nice bathroom facilities and hot showers, which was perfect for the cooler fall days. It's a busy park so you'll need to reserve early or plan on visiting during the week.
The hiking itself was awesome. We did the Dakota trail, which was a tough up and down hike with really incredible views of the fall colors. There's also a nice park/picnic area with beach access. I'm hoping to come back next summer to enjoy the swimming. All in all it was a great stay!