We had at 8am reservation. We stayed onsite, but drove our own car to the parks. We arrived at AK about 7:40 and there was no one to be found at the place where you pass through to park. We had to wait until 8am until anyone showed up to let people in. By 8am there were a line of cars waiting to get in. We were a few minutes late for our reservation, but had no problems. I would plan to get there a little early, so you are toward the front of the line of cars.