Image: T J OBrien Lock and Dam

Description: Aerial view of T.J. O’Brien Lock and Dam on the Calumet River, which is part of the Illinois Waterway. The dam is situated at river mile 326.5 on the Waterway (326.5 river miles up from the Mississippi River). T.J. O’Brien lock is the uppermost lock on the waterway, and there is not another barrier between the lock and Lake Michigan. There is very little elevation change in the lock, which serves mainly to regulate water flow from Lake Michigan into the waterway. The dam is located in Chicago, Illinois.
Title: T J OBrien Lock and Dam
Credit: U.S. Army Corps of Engineers Digital Visual Library Image page Image description page Digital Visual Library home page
Author: Carol Arney, U.S. Army Corps of Engineers
Permission: This image or file is a work of a U.S. Army Corps of Engineers soldier or employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain.
Usage Terms: Public domain
License: Public domain
Attribution Required?: No