Times are posted on the park for all lectures.
You can see them anytime. The lecture is early afternoon I think. Its Great, park is Great! Nice, handicap accessible, shade, places to sit along path, nice gift shop, friendly outstanding employees. Enjoy, relax. Grab lunch, or ice cream.
Call them
There's a observatory where they can be seen even if lectures aren't going
They are posted as you walk in or on of the very helpful guides can tell you.
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