The zoo was started when a circus lion cub ended up on James T. Miller's farm around 1900, and was eventually given to the city of Bloomington.

After Big Jim's death, funds were raised to construct the Koetthoefer Animal Building by Bloomington architect Arthur L.

In the mid-1970s, the Woodland Wing became the Tropical Rainforest Exhibit, the Animal Building was updated, and the sea lion/otter pools were built.

Entryway – Greater flamingo DeBrazza exhibit – De Brazza's monkey Tropical America Rainforest – saki monkeys, scarlet ibis, troupial, Silver-beaked tanager, Violaceous Euphonia, Nicobar pigeon, saffron finches, cotton-top tamarins, prehensile-tailed porcupine, callimico monkeys, agouti, and more Tortoise exhibit – Galapagos tortoise, Radiated tortoise, Asian brown tortoise North America – bald eagle, red-tailed hawk, burrowing owl, ringtail, eastern box turtles Wolf exhibit – red wolf ZooLab – axolotl, walking sticks, giant cockroaches, budgerigar, green aracari, smoky jungle frog, mimic poison frog, and much more Australia – tammar wallaby, wallaroo, laughing kookaburra, tawny frogmouth, salmon-crested cockatoo, and galah Children's Zoo – San Clemente Island goat, Randall Lineback cow, chickens Other exhibits – American alligator, Eurasian eagle owl, red panda, red ruffed lemur, Pallas's cat, hooded crane, guanaco goose and koi pond Katthoefer Animal Building – Reticulated python, Müller's gibbon, Francois' langur, Sumatran tiger, snow leopard (tiger feedings at 4:00 pm)[2] River otters – North American river otters (feedings at 11 am and 3:00 pm)[2] The Junior Zoo Keeper program began in 1972, and at first was open to students starting in the second grade.

[5] There are currently plans to make major renovations on the Animal Building to bring it up to date, and also to redesign the ZooLab in order to create a new guest experience.