For International Polar Bear Day, I’d like to recount an entertaining story I recently stumbled upon while researching zoo history. And you will be happy to know that I can call it entertaining because no people or animals were hurt in this escape story. And who doesn’t enjoy an entertaining, benign escape story?
For a zoo employee, no day is ever the same—you never know what challenges or rewards you will face on a daily basis. But imagine coming to work and finding seven polar bears pillaging a concession stand, chowing down on sugary goodies. That’s exactly what happened on the wet, soggy morning of July 17, 1969.
The Brookfield Zoo, located in suburban Chicago, prides itself on being the first zoo in the United States to incorporate cageless, moated exhibits. These natural settings were a request from Edith Rockefeller McCormick (daughter of John D. Rockefeller), who donated 83 acres of land for the specific purpose of creating a modern, innovative zoo modeled after the cageless exhibits she admired in Europe. Zoo construction began in 1926 but was halted during the Great Depression; the zoo finally officially opened in 1934. Not only did it gain international recognition for its moated exhibits, but it was also the first zoo in America to house giant pandas (Su-Lin arrived in 1937), which drew millions of visitors through its gates during its first decade of operation.
The moated grotto exhibits, often cited as favorites, gave visitors an unobstructed look at the animals and allowed them to throw food to the begging bears—a very common practice at zoos in those days. In fact, the Brookfield Zoo had a concession stand right across from the polar bear enclosure that sold marshmallows for bear feedings in addition to human treats. The polar bears could watch that stand every day, all day in hopes that visitors spent their coins on goodies for them.

The moats and marshmallow combo worked out well for the bears and visitors entertainment-wise, but the zoo wasn’t prepared for what happened in the summer of ’69.
Between the evening of July 16 and the early morning hours of July 17, Chicago experienced torrential downpours. Flooding was so bad that even the deep moats in the polar bear exhibit flooded, creating a pool instead of a barrier. The seven (yes, SEVEN!) very smart polar bears were able to swim out of their enclosure and made a bear-line right for the refreshment stand that had taunted them every day for years.
When employees arrived the early morning of the 17th before the zoo opened, the bears had already broken the concession stand windows and had finished the supply of marshmallows. They had moved on to the stash of ice cream and chips, as well as tossing around a cash register.

When approached by the zoo employees, five of the bears immediately swam back into their enclosure. One had run over to say hello to the grizzly bears, who wanted no part in a cordial visit from their neighbor. The other bear made a run for the zoo restaurant, but guards, using vehicles with sirens and horns and firing a few shotgun blasts in the air, were able to redirect it back towards the polar bear exhibit. The bears didn’t need to be tranquilized, but the guards were prepared to do so if necessary. The local fire department was immediately called in to pump out the flooded water while the bears were kept busy with more marshmallows.
The incident made the national news, and a children’s book, The Marshmallow Caper, was written about it. It was also the first time in the zoo’s history that the gates had to close, as it is normally open 365 days a year. Luckily it was an event that could be looked back on with chuckles instead of tragic evocation. Keeper Jim Rowell remembered, “It sounds funny now, but any time an animal escapes it can turn into a nightmare.”
I could not find any details about modifications the Brookfield Zoo made to prevent the bears from escaping again, but the zoo did end the sale of marshmallows and prohibited animal feedings in 1970. Sorry, bears.
Da Bears 1, Humans 1.
Sources
“Brookfield Zoo (Chicago Zoological Park).” Encyclopedia of Chicago. Edited by Janice L. Reiff, Ann Durkin Keating, and James R. Grossman. Chicago: Chicago Historical Society, 2005. http://www.encyclopedia.chicagohistory.org/pages/172.html
Deuchler, Douglas, and Carla W. Owens. Brookfield Zoo and the Chicago Zoological Society. Images of America Series. Chicago: Arcadia Publishing, 2009.
Krizmis, Patricia. “After Deluge, 7 Bears Find Way to Marshmallow ‘Eden’.” Chicago Tribune (July 18, 1969): 1:
“Polar Bears at Illinois Zoo Swim Moat, Devour Snack Stand Sweets.” Washington Post (July 19, 1969): A3.
“Polar Bears Swim Zoo Moat to Feast on Marshmallows.” New York Times (July 18, 1969): 35.
“Zoo Escapes Funny in Retrospect.” Bangor Daily News (November 21, 1992), https://archive.bangordailynews.com/1992/11/21/great-zoo-escapes-funny-in-retrospect/