Website says 5pm. Unless you're camping.
Once you enter the park during normal hours most allow you to be there till dusk (again if you have a camping site, cabin, or villa you have access all night till your check out) but the park rangers and store close at 5pm. You will not be locked in at this park the gate is open throughout the night for campers to come and go. There are camp hosts and rangers that will check and make sure only authorized people are there after dusk.
I think thats when the facilities close. Like the store and stuff.
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