Devils Tower National Monument Travel Information by admin September 19, 2022 Spanning over an area of 1,347 acres, the Devils Tower is a monolith – an igneous intrusion of phonolite in Crook County, Wyoming in the Unites States. The Devils Tower… Share this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Pinterest (Opens in new window)