Looking west in 1961 at the new bridges for the Wabash Railroad and to its west, Southwest Highway. The railroad bridge is complete and the plug of old channel bank beneath it will be removed. The highway bridge was built earlier, but its vertical clearance is less than required. New foundations will be installed allowing the bridge to be raised. All widening of the channel occurred to the south. (Undated photo courtesy of the Worth Historical Museum)

Looking east southeast, the four bridges from front to back are: Southwest Highway, Wabash Railroad, Harlem Avenue, and Ridgeland Avenue. As of 1963, two bridges have yet to be replaced and widening has not been completed for the Harlem and Ridgeland crossings. Few vacant lots remain in Palos Heights on the right and Worth on the left. The white rectangle at right is an oxidation pond. (Undated photo courtesy of the Worth Historical Museum)

The same view as the prior photo, looking east, shows more of Worth. The former North Drainage Ditch follows the zigzag between the Wabash Railroad and Ridgeland Avenue. The open space is owned by the District and was used for spoil disposal when the Calumet-Sag Channel was built. The oxidation pond is presently buried near Lake Katherine. (Undated photo courtesy of the Worth Historical Museum)

From above the Harlem Avenue bridge, three barges and a pusher head east toward Ridgeland Avenue. Single file is the rule until the remaining narrow channels at unfinished bridges are widened. At present, most land along the channel is used for recreation, including the Cal-Sag Trail on the south bank. (Undated photo courtesy of the Worth Historical Museum)

Looking southwest, a diversion for Harlem Avenue has been completed and construction is about to begin on the new bridge in late 1964. On the right, a ditch follows the route of the former Worth Road. A development is underway west of Harlem and north of College Drive. Palos Heights is unincorporated. (Undated photo courtesy of the Worth Historical Museum)

Widening the Calumet-Sag Channel shortened the length of the outlet for Mill Creek and may have caused channel erosion were it not for the rocky streambed and numerous rock ledges. Looking north from the Cal-Sag Trail bridge on August 21, 2019, shows the rocky streambed. At this writing, the Cal-Sag Trail extends from Cicero Avenue to the Sanitary & Ship Canal. (Photo by author)

Navajo Creek flows north into the Calumet-Sag Channel west of Ridgeland Avenue. It is a shorter creek with a lower gradient than Mill Creek. To retard upstream erosion and down-cutting of the streambed, a series of simple low dams were installed. Looking south from the Cal-Sag Trail bridge on August 21, 2019, one of the sheet pile dams is visible. (Photo by author)

The Harry “Bus” Yourell Sidestream Elevated Pool Aeration (SEPA) Station is on the north bank of the Calumet-Sag Channel east of Harlem Avenue. Built in 1992, it is one of five SEPA Stations that supplement dissolved oxygen in the waterway to meet water quality standards and improve aquatic health. A pumping station out-of-view at left lifts water from the channel to flow through ponds and cascade back to the channel. (MWRD photo 061908_1148)

Five new longer railroad bridges over the 250-foot wide channel replaced four short railroad bridges over the original 60-foot wide channel in Blue Island. Looking north from Broadway Street on March 11, 2020, two dual-track main rail lines cross south of the channel. On each side, two dual-track bridges carry connecting tracks. A single-track bridge in the center is not in use. (Photo by author)

Looking south from Broadway Street on March 3, 2020, the many tracks south of the channel disperse east and west. The crossing of so many rail lines at the channel presented an engineering challenge to accommodate several railroads. Two large rail yards southeast in Riverdale show how critical the channel crossing was to freight movement in the metropolitan area. (Photo by author)

The Thomas J. O’Brien Lock and Dam was built by the US Army Corps of Engineers and placed in service in July 1965, replacing the Blue island Lock. Looking south, the modern lock can accommodate as many as 12 standard barges plus a pusher. The dam contains four sluice gates for regulation of flow from the Lake Michigan watershed. It is rare for floodwater to be discharged to Lake Michigan. (MWRD undated photo)