No, they have a gate that shuts at sunset. You are allowed to go around the gate in person.
Yes. The trails are open until 8 during the summer, and until 6 in the winter.
The main building that houses exhibits is closed at 5pm. The trails are still open until sunset which is whatever the national weather service has recorded for that day. The gate has a sensor that will open as you approach it to leave but not enter.
Thanks! Your answer is awaiting moderation.