Although preserved for its cultural significance, Fort Bowie NHS also encompasses a variety of natural features - such as springs, faults, and numerous soil types - which result in the wide array of flora and fauna found here. The Apache Pass fault, a visible fissure which can be seen on the Overlook Ridge Trail, is the source of the water that rises up into Apache and Siphon springs. The fault was formed when a block of limestone was overthrust and then folded over a block of granite, which are the two major rock types found here. Helen's dome, a mostly bare tower of granite, served as a landmark for travelers approaching Apache Pass.
Did You Know?
Prairie falcons sometimes nest in the cracks of Devils Tower. Climbing routes near the nest are closed until the young falcons fledge.