Long time on my bucket list of things to do. The views were fantastic and awe inspiring. Definitely take a walk around Devil's Tower, the paths are nice and well kept, and you get to see the size of the rock that have fallen hundreds of years ago. There are often climbers climbing the Crags up to the top. If you get a chance, talk to a couple of them, it's very interesting. We ended up spending several hours walking around, while other people were just walking around Devils Tower in 30 minutes or so. I would definitely suggest taking your time and enjoying the view of one of Nature's wonders.
Try to get there early in the day to get parking, and to walk around the tower while it is still cool. Bring water. The only facilities are in the main buildings. The kids enjoyed the Junior Ranger program, and the ranger explained the geology of the tower and the significance of the site to the native peoples. The month of June is spiritually important to the native people, so visitors are reminded to be respectful. Bring binoculars if you want to watch people climbing the tower. The size of the tower, and of the basalt columns is hard to grasp until you examine the rocks in the scree field and find the hexagonal (and sometimes 4-, 5-, and 7-sided) chunks of columns.
It's hard to comprehend Devil's Tower when you see it, there's nothing like it out there. It's pretty easy to get to, and a short drive takes you from the entrance to the visitor center. The visitor center was very informative as to how Devil's Tower likely formed (they're not completely sure). It's a short hike to the base of the tower, where you can sit/stand and stare. It's beautiful on a sunny day, I went in February when it was almost empty. Was definitely worth the trip, it's a very memorable place. PS - did not see any aliens during my visit.
This is a must see. The Peregrine Falcons were amazing. The prairie dogs coming into the park are the cutest ever. You can climb all over the rocks. Relax and take some pictures. Its exciting driving towards this monument because you can see it from so far away.
A truly great place to take your time to visit. My kids loved the experience, and my wife and I the same. It was a great campground, close enough to walk past the prairie dog town and head up to Devil's Tower. Will visit again, pretty awesome when the tower comes into view on the drive in. Beautiful drive to get there too.