We arrived at Zion on a Thursday evening in mid-November'19 without any plans. The Zion South Campground is closed for the season at this time, which we were unaware of. We did not have a reservation, and the sign at the entrance said full. We drove around a bit anyway.

In the 'F' loop, which has access to the walk-in sites, we noticed a parking spot without a reservation tag. So we knocked on the door of the on-duty campground host to ask about its availability. Sure enough, it was a no-show and they allowed us to stay after paying the standard $20 fee. The host made sure to explain how rare this occurrence is and we shouldn't bet on it in the future. Worth a try though if you have no other plans!

It is a very short walk from the parking lot to the 'walk-in' campsites. Maybe a few hundred feet. Sites are pretty close together, and the walk-in sites do not have their own fire pit. Instead, they have a few communal fire pits with benches around.

The sites each have a nice flat tent pad, an awning for shade, a picnic table, and a bear box.