Chain of Rocks Lock

Chain of Rocks Lock is a navigation lock on the Mississippi River in Madison County that connects different water levels along the river. The facility consists of a main channel roughly 1,200 feet long paired with a smaller auxiliary lock about 600 feet in length.

The lock opened in 1953 to help vessels navigate through a dangerous rocky section of the river that caused problems especially during low water periods. The project was part of broader efforts to make the Mississippi suitable for modern freight transportation.

The lock represents a major achievement in American engineering, demonstrating the adaptation of natural waterways for commercial transportation needs.

The lock handles more cargo than any other navigation facility on the Mississippi River, operating around the clock to keep vessel traffic moving. Visitors can observe from several viewing areas to watch ships move through the locks.

The facility incorporates roughly an 8-mile canal system and uses natural rock formations as a weir instead of a traditional dam. This design approach utilized the existing landscape to reduce costs and minimize environmental impact.

Location: Madison County

Location: Venice Township

Elevation above the sea: 125 m

GPS coordinates: 38.70310,-90.18080

Latest update: December 8, 2025 19:51