Permit required, very difficult hike, trail not marked very well. Not many hikers out there and no cell coverage once you start descending. No shade throughout the hike. There is a helicopter landing pad, but not sure who provides travel service. River is absolutely amazing with the turquoise color. Keep an eye on weather as rain within a week can turn water brown. I did this in a day, but would recommend staying the night to recuperate. General recommendation is to do this hike with at least one other partner, make sure you are in good shape, and bring plenty of water and electrolytes. Also bring a headlamp in case you get stuck in the dark. Worth the effort, just be safe out there.