24 hours Year Round Lock and Dam 4 is one of eight major river facilities on the Allegheny River.
Visitors can view locking operations from the parking area or while touring the facility.
745.4 History Lock and Dam 4 was built from 1920-27, and opened in 1927. Project Lock and Dam 4, like all navigation facilities on the Allegheny River, consists of a single lock chamber and a fixed crest dam. Water which flows over this type of dam cannot be controlled locally. Consequently, it cannot provide any control over flood waters. An incidental benefit derived from the pool formed by the dam is the availability of a source of municipal and industrial water.