If I got an early reservation time, could a guy go in early, then turn around an leave and then come back later that day after the assigned 2 hour window?
I am not sure, if you could, you would have to get in the line getting back in which has been stupid long in the afternoon. I am inclined, for that reason, to think you can't. The time window is a 2 hour block, like 7-9 am. There is a $2 cost for each time reservation (get it on the rec.gov? site?
If you knew the timing, you could make more than 1 reservation/day.
A bit wonky but it would be a mess if they didn't have it in place, EVERYONE is heading there right now.
Also, be sure that you get the full access including Bear Lake (assuming you want to hike up in that area). You can get a version without that but don't know why anyone would. same cost.
And previous post was correct, parking at bear lake and shuttle ride to bear lake fills up fast