I posted this under a boating thread, but thought it would be better here as a new thread.
Next Saturday, May 19, the Alaska ATV Club is doing thier annual Knik River cleanup. They usually take out tons (literally) of stuff. Everything from gum wrappers to car bodies. They try to get to the entire river, not just the parking area.
More info at: www.alaskaatvclub.org/spring07flyer.htm