When he still lived in a building overlooking Humboldt Park, Mark Pepp was given Stanley Applebaum's The Chicago World's Fair of 1893: A Photographic Record as a gift from a friend. While perusing its pages, he noticed that the twin bison sculptures parked just in front of the east entrance to Humboldt's formal gardens were also pictured in his book, perched atop one of the White City's magnificent bridges.
Upon further investigation—including an e-mail to the Chicago Park District—Pepp discovered that the sculptures came about in 1909 when landscape architect Jens Jensen was commissioned to create two outdoor art exhibits: one in Garfield Park, the other in Humboldt Park. Jensen enlisted the help of various Chicago institutions to recast bronze models of the original bison, which were first created by Edward Kemeys—the same artist behind the lions that crouch on the steps of the Art Institute—for the Chicago World's Fair. The collaboration resulted in both the Humboldt Park bison and a pair of bronze bulls that now stand behind the Garfield Park Conservatory. These bison are slightly different than the originals—one is a male figure called "Prairie King," the other a female called "Sounds of Whoop," perhaps in anticipation of all the shiny, happy people who flood the park come summertime.