This is a difficult one way trail in Arizona. From Hilltop to Supai it is about 8 miles. From Supai to the campground you are looking at another 2 miles. The campground itself is 1 mile long. Be sure to have your campground or hotel reservations in order before you set off on the hike.
The first mile or so are switchbacks from hilltop to the bottom. Once you are on the bottom the hike is pretty mellow and easy. Be on the lookout for mule runs. The come up on you quick and are large. Get out of their way.