Army Corps of Engineers Green River Lock and Dam No. 6 near Brownsville, Kentucky, was built in 1904-1905 and put into operation in 1906. Wooden barges hauled asphalt and sandstone. The project was closed in August 1951. 

A decision was made to remove the lock and dam because it was failing in place and posed safety risks. An uncontrolled breach occurred in November of 2016. There was a failure in several sections of the dam to include structural damage, such as cracking and tilting of the lock walls. Federal legislation was signed in December 2016 deauthorizing the dam from the Corps inventory and directing its removal.

The biggest concern and reason for pursing the removal was to address the risk to public safety for those visiting the area to kayak or canoe. The dam's removal means that the river will be open for recreational traffic with better access, especially kayaks and canoes, and will increase tourism with economic benefits to local businesses. 

Removing the dam also allowed the Green River to take on natural characteristics of a free flowing river system. Without the dam, unnatural water levels will be eliminated within a large part of the Mammoth Cave improving riverine habitats for aquatic organisms including endangered mussels, darters and sport fishes such as smallmouth bass and muskellunge. 

The Green River is one of the most biodiverse rivers in the country. It is home to more than 150 fish species, more than 70 mussel species and many threatened or endangered species.

Removing the dam was performed by experienced personnel under an interagency support agreement between the U.S. Army Corps of Engineers, Louisville District and the U.S. Fish and Wildlife Service. Other participating agencies are Kentucky Department of Fish and Wildlife Resources, Mammoth Cave National Park, The Nature Conservancy and Kentucky Waterways Alliance.

The lock walls were removed and debris placed in the lock chamber. The slopes were graded and seeded to look just like the river bank. Biologists expect floods or high water to transport tree seeds to the exposed soils where to sprout and cover the slope within one to three years. The lock and dam were removed using hydraulic hammers with some of the excavated rock being placed in the lock chamber. The removal took approximately 16 days. An experienced dam removal team with Fish and Wildlife service who specialize in this unique demolition had done similar work in Texas and North Carolina and up the east coast.