Jellystone Park in Larkspur check-in time is 2 pm every day, and the check-out time is 11 am. As for the front office, it’s open from 9 am to 5 pm every day. They’re very helpful in there. So if you need anything, head over there as their doors open at 9 am because they do get busy. For the rest of the amenities and facilities, they close up at 10 pm.