Chattahoochee Bend State Park is an almost brand new state park located near Newnan, which is roughly an hour from Atlanta. The state park has a very nice boat ramp with a trough beside it lined with artificial turf. When you drag your boat up the trough it cleans any mud off of the boat. You can put in a couple miles upstream from there where GA-16 crosses the river. The put-in also has a nice ramp, port-a-potties and a nice parking lot. There are some mild rapids but the riverbank through there is mostly undeveloped so it's got a nice wilderness feel to it.
Classic Freestanding Rack