You need a boat for Mosenthein Island, but not for Chouteau-Gaberet Islands. The road back to the 1 parking area can be ruff. I use my bicycle to get to my favorite spot. It is a 2 1/2 mile ride from the parking area. It can be busy on the weekends.
I made a rack to carry my stand and equipment for my bike, and a cart which attaches to the back of the rack to haul deer out.