A small zoo displaying local animals—including bison, coyotes, and elk—was briefly added during the 1920s, but the terrain was soon deemed insufficient for grazing so the animals were removed. However, the park still housed animals on a rolling basis, particularly during the winter months, until the Great Plains Zoo was established in nearby Sherman Park in 1963. During the 1950s up until 1963, monkeys and lions were kept over the winter in the 1884 Phillips estate carriage house, which earned the building the nickname the "Lion's Den". It still stands today and is the last remaining building from the Phillips estate era.
