Paved yes. Reserveable yes
You can make reservations on the website. It works like all the other government run campground reservations. I'd say it's about a 20 minutes drive to Snowmass, you have to go through Aspen to get there so it really depends on traffic. Last summer they had a bunch of roadwork so it took a bit longer. All the roads are paved, though a bit rough. It is fine in a minivan. You'd want to take it slow in a McLaren.
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