This is the first time I've ever posted to this forum but I've ran into this issue myself. Specifically with the ramp at Rice Camp down DD. Just recently as last summer they put up a "Donation Box" by the ramp but the sign by it reads like you have to pay( a little misleading for obvious reasons). No biggie except the homeowners have recently tried running people off the ramp with or without donation with threats such as calling the Sheriff. This happened to my dad last summer and again to me a couple weeks ago. They have went as far as to stretch yellow caution tape across the road. When this happened to my dad last summer he called the COE and they said that its still a public ramp and donations are optional. In other words they cannot run you off or make you pay. I agree that the larger ramps are more convenient especially with the courtesy docks and parking, but sometimes these smaller ramps get you a little closer to where you wanna fish.
Also my parents use to own a small resort on the lake and the COE told them if they ever put in a ramp that it would have to be open to the public.