Santa Elena Canyon, Big Bend National Park

In places, Santa Elena Canyon’s towering 1,500 foot walls are only 30 feet wide where the Rio Grande River courses through it today. About eight miles long altogether, some visitors experience Santa Elena Canyon via multi-day float trips starting outside Big Bend National Park, but you can also hike partway into the canyon via a 1.6 mile out and back hiking trail. Hikers do have to cross Terlingua Creek and then climb a short but rather steep bank to enter the canyon.