It depends on the ride you go on. The one that we went on was about 20 minutes out, a half hour at a small park in the valley for refreshments and stories by a librarian, then 20 minutes back. They have "excursions" that are about 2 hours. You should see the website for the schedule of those.
1 1/2 hours was what i heard
The ride lasts about 1 1/2 hours. Very nice.
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