Locks · Chicago River
Chicago Lock: 2,845 lockages and 8 barges
No federal lock locked through more often. Almost none of it was freight.
Chicago Lock sits at mile 327.2 of the Chicago River, where the river meets Lake Michigan in Chicago, Illinois. Between 4 September and 4 October 2026 it logged 2,845 lockages, more than any of the 173 locks with traffic in our archive. That is about 7% of the 41,054 lockages we recorded nationwide. Only 8 were commercial, and they carried 8 barges between them.
A lock for light boats
99.7% of lockages were recreational or light boats. The lock averaged 92 lockages a day. The busiest day was Saturday 5 September, the start of the Labor Day weekend, with 162. Saturday was the busiest weekday across the five weeks, and 6 pm the busiest hour.
Traffic split evenly, with 50% of lockages upbound. By barges, Chicago ranks 148th of 173 locks. The single chamber is 600 by 80 feet, with a 4-foot lift, and it opened in 1938.
Across the archive, 24,818 of 41,054 lockages were commercial and they moved 139,931 barges. Chicago contributed 8 of those barges.
The eight commercial lockages
Each commercial lockage moved one barge. The median wait was 4 minutes, and so was the longest: the downbound Ruth Anatasia, which arrived on 5 September. Middle River Marine accounted for 2 of the 8 lockages. The other 6 came from boats we could not match to an operator.
Live status
The lock runs 24 hours a day, every day. Its notice on the morning of 4 October reported outdraft conditions, with no restrictions, an upper pool of 579.83 feet and a lower pool of 577.42, a difference of 2.41 feet. At 10:06 UTC on 5 October the Corps reported no tows waiting, with 45 upbound and 42 downbound lockages in the previous 24 hours. Since live status began on 4 October, no more than 4 tows have been waiting at once.
The live Chicago Lock page updates every 15 minutes.
Sources: U.S. Army Corps of Engineers Lock Performance Monitoring System, archived by Lock Wait; chamber dimensions and opening year from the BTS National Transportation Atlas; operators from the USACE Waterborne Transportation Lines (2022) and FCC ship licences. Wait is measured from arrival to start of lockage. How every number is defined.