High Bridge was my go to launch for years. After living in that area all my life I moved to retirement so this stuff pisses me off, but, you guys need to set up your own sting and catch them in the act, block the exit and call police. When you block the launch, make sure there are about ten of you standing in the way.
You are going to have to give up some fishing time, but this will not stop and the police are not going to help!