It's a butte that caused several dad jokes, but thought to be either solidified lava off a volcano that eroded a long time ago or some sort of geologic abnormality.Or caused by a large demon bear trying to get at a tribe of hunters purched at the top.
Or just one of Ymir's molars (sorry, viking joke).
We went into the park, and be warned there is a significant wait to get close to it depending on the volume of people there. We waited almost an hour on a normal week day. Make sure your gassed up and feel free to turn off the vehicle.
The wait was well worth it.
It's a national park so there is a no drone policy. We were also there in June when they allow for Indigenous ceremonies and nesting birds so there were no climbers on it. We took the 1.7 mile walkabout around the base. Someday I may go back and do the nearly 5 mile tour, but had limited resources (water) on me.
The views were well worth the hike and Devil's Tower appears different from all angles.