I would absolutely recommend Devils Tower. If you are traveling to/from Yellowstone N.P. (from the east) Devils Tower can be made into an easy stop. Or, if you are in the Black Hills, Devils Tower can be coupled in with a trip to Deadwood, or the Black Hills Passion Play (in Spearfish). Upon arriving to Devils Tower, the question you will need to ask is...to pay, or not to pay for park admission. You will get fabulous views from the highways that surround the monument. Inside the park you will find a visitor's center, a hiking trail at the base of the monument, and a very enjoyable prairie dog field. If the park is busy, I would recommend viewing the monument from outside the park. There are souvenier shops just outside the park entrance if you'd like gifts. We entered the park and hiked around the tower...personally, I wish we hadn't paid for the admission price. Either way, you'll surely enjoy Devils Tower.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.