The Binghamton Zoo at Ross Park sits tucked into the northern face of Binghamton's South Mountain. The zoo officially opened in 1875, and it is the fifth oldest zoological institution in the country behind such communities as Philadelphia, Chicago, Cincinnati, and Buffalo.

A wealthy businessman, Erastus Ross, who stipulated that the land was to be used as a park for all the community to enjoy, donated the 90-acre plot to the city of Binghamton. The first electric-run trolleys in Binghamton were in 1887, and a line running up Park Avenue by way of the old Washington Bridge created easy access to the park. A roller coaster, swings, and a variety of other amusements helped Ross Park to flourish into a busy and popular recreational area. The stone pillars were erected in 1896 and welcomed visitors as they arrived by carriage or trolley. In 1919 Ross Park saw the arrival of a bear exhibit, and the park's carousel.

The increased use of the automobile allowed people to travel out of the Binghamton area for recreation, decreasing the number of visitors to the parks. The loss of this revenue caused the zoo to slowly degenerate. Two World Wars and the Great Depression helped to continue the decline of the Ross Park Zoo until the USDA (Dept. of Agriculture) threatened the zoo with closure.

In 1966, concerned community residents formed the Southern Tier Zoological Society, and for the first time in 1972, an appropriation for zoo maintenance appeared in the City of Binghamton's budget. The Society was granted a contract by the City to oversee the operation and maintenance of the zoo in 1977, and has assumed additional responsibilities ever since. The Zoo was first accredited on 1987, and has been re-accredited in 1992, 1997 and 2009 by the AZA (American Zoo and Aquarium Association).

Under the Southern Tier Zoological Society, Ross Park has undergone tremendous changes. What was once asphalt, concrete and steel bars is now winding wooded paths with naturalistic exhibits housing over 100 different species. A strong emphasis on conservation education has created an outreach program that serves over 20,000 people in New York and Pennsylvania.