Bubbly Creek is the nickname given to the South Fork of the Chicago River's South Branch, which runs entirely within the city of Chicago, Illinois, U.S. It marks the boundary between the Bridgeport and McKinley Park community areas of the city. The creek derives its name from the gases bubbling out of the riverbed from the decomposition of blood and entrails dumped into the river in the early 20th century by the local meatpacking businesses surrounding the Union Stock Yards directly south of the creek's endpoint at Pershing Road. It was brought to notoriety by Upton Sinclair in his exposé on the American meat packing industry entitled The Jungle.