Designed by Victor Borchert with planning assistance from Saco Reink DeBoar, Bear Mountain was constructed in 1918 and completed in 1919. It was the first "natural habitat" animal enclosure in the United States. Bear Mountain was a prototype to be implemented in zoos throughout the United States thereafter. Since its completion, it was the home to grizzly bears, polar bears and Himalayan bears. The last bears moved out in April 2019. The facility is vacant and underappreciated for its pioneering concept in the design of 20th Century zoos.