No unless doing a tour or group program
If you want to stay at the lodge or a campground, you need reservations. If you just want to go for a day visit you do not need reservations.
If you plan to stay within the GC lodge then you have to do reservation. It is generally booked atleast a year in advance.
Depends what for?
No, it is open to the public prior to entry control
No reservations are required. You can walk right in.
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