Okay, I'm here, and my destination is on the other side of one of the
Great Lakes. Flying direct will take me out of gliding distance from
shore, so I don't want to do that.

.... but there's no obvious airway route around the lake. In fact,
there's a big honkin' Class B area, so even if I try to file a route,
it'll probably be reassigned anyways. So, I just want to be open to
receiving an assigned route, just not one that takes me over the lake.

So, what's the best way to ask for a route assignment that doesn't go
over the lake?

1) Put it in the filed plan? In the route? Or "NO LAKE OVERFLIGHT"
in the comments? Or something else?

2) Tell the controller when I pick up my clearance?

3) Wait for an assigned route, and if it goes over the lake, tell the
controller "unable"?

4) Move to a different state?