Some parks turn you away at the gate without a timed-entry reservation or permit — and the windows sell out fast. Pick a park to see what it needs, when, and where to book it.
We reviewed this park and found no timed-entry reservation, permit or lottery for a normal day visit. Just show up — an entrance fee may still apply. Specific backcountry or wilderness permits can differ, so confirm on the official page before a longer trip.