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. Gases bubbling out of the riverbed from the decomposition of blood and entrails dumped into the river by the local stockyards in the early 20th century give the creek its name. The area surrounding Bubbly Creek was originally a wetland; during the 19th century, channels were dredged to increase the rate of flow into the Chicago River and dry out the area to increase the amount of habitable land in the fast-growing city. The South Fork became an open sewer for the local stockyards. Meatpackers dumped waste, such as blood and entrails, into the nearest river. The creek received so much blood and offal that it began to bubble methane and hydrogen sulfide gas from the products of decomposition. The creek has remained toxic to the present day; a resident in the 1950s and '60s remembers the air being "rancid". While the area has been increasingly occupied by residential development such as Bridgeport Village, some wildlife and vegetation has returned in recent decades.