Wow! Awe inspiring.
I must say, this was the site I was least excited about experiencing before the trip. I just kept thinking, "why do I want to see a big rock?" This ended up being one of my favorite parts of the vacation. This is not a big rock, it's an overwhelmingly huge feature. We could see it from miles away on our drive in. And even that far away, it was breathtaking.
The path around the tower is easy. You could walk it easily in 30 minutes, but we took our time, climbed some of the lower rocks, took pictures of the wildlife and just sat to soak up the nature. We spent about 2 hours.
Note that parking near the entrance of the path (near the visitor's center) is extremely limited. We arrived early and there were several spots, but there were none when we left about noon time.
Don't miss the prairie dog farm on the drive up to the tower. They have no fear, so you can pull over and get some great pics.