Started from Perry Riffle trailhead. We took the old Yana trail, which isn't maintained anymore. The old trail runs 3.5 miles. The new Yana trail runs 4.5 miles. Pretty flat and easy to navigate.
Two points in the old trail to be aware of. First, at some point you will hit a creek. You will have to climb down a ladder that can be slippery if it's raining. Also be aware that the creek has a lot of mosquitoes. I stood by the creek for about 5 minutes to make sure the rest of our guys got down ok and got bit 3 times.
Second, part of the old Yana trail looks like it fell during the January storms. Other hikers made their way around the collapsed part of the trail. If you hit the collapsed part, just go back about 10 to 15 feet and you'll find the other trail that goes around. You'll be making your way through some tall brush since the old Yana trail isn't maintained and folks made a bit of a new one to get around.
Campsite has everything you need. There is an outhouse and three or four firepits. If you keep going past where the trail fades and make your way up the hill, you'll get a great view of the river bend that you can't see from your campsite. There is also an outhouse.