rallison, thanks so much for that recommendation!
Don't worry folks, I've pretty much decided against taking the kid up GMR. But the 39 route sounds enticing. I also like the idea of riding beach paths, but again, my point is to get away from crowded areas and expose my kid to the awesomeness of mountains. It's good to have variety.
As for this Saturday, I've got a babysitter lined up and I'm planning my first long solo ride in a month. Maybe I'll scope out 39 as rallison suggested.