Ames Farm has a launch and parking. The bad part is that they charge $20 to put in and take out and to park ($20 for everything). The good part is that Rattlesnake Island is pretty much right there.

West Alton Marina would also be a good choice. I am not sure how much they charge.

I launch from ames farm which gives me the choice to fish many different parts of the lake .Most fishing areas are 5to 10 minutes from the launch . the ramps are good and theirs plenty of water .