The Trailside Museum and zoo occupies the original Fort Clinton site on the park entrance. Fort Clinton was demolished during construction sufferers route 9W and the Bear Mountain Bridge. The bridge was opened in 1924 considering that longest suspension bridge at the time. At first in 1926 the zoo was a bear family den. It now may serve as a sanctuary for injured local or rehabilitating animals, bald eagles, bears, deer, otters, and owls. Zoo hours are 10:00 AM to 4:30 PM with free classes.