2gypsies wrote:
We, as full-timers, have stayed inside of Yellowstone, Grand Teton, Glacier, Bryce, Zion and yes, even Grand Canyon at Trailer Village and many more parks without reservations. Some national parks even have campgrounds that don't accept reservations.
So have we, years ago. Trailer Village, Yellowstone and Yosemite need to be booked the morning they come available, or you won't get a spot. There will always be cancellations and if you're travelling by yourself, you might get lucky. I don't plan trips on getting lucky after driving there.