There's a large parking area for leaving vehicles while you're on the water but secure anchors may be hard to find. There are some campsite parking spots adjacent to a heavy steel chain that you should be able to chain the dirt bike up to but you should check on this first with the ranger. The launch calendar is full for this Saturday, and that they started staffing the ranger station in the first part of the month so you should expect to see the ranger there. I'd recommend you ask where you can chain up the bike when you see him, preferrably before you run shuttle.
Anything else we should know for an early season overnighter?
make sure you've got warm gear and also have everything that's required by the permit.
have a good trip!