[1] Improved drainage works were completed in October 2011 and although studies are still underway, the dam was declared safe to maintain its maximum reservoir level.

The Green River Valley was settled in the 1850s and became a notable farming area, until an aphid infestation destroyed the large hop crop in 1890.

[2] It was not until 1936 that community leaders, citizens and with additional effort by Congress, the U.S. Army Corps of Engineers (USACE), Seattle District began to search for a suitable flood control project site on the Green River.

The selection was delayed by the Second World War and finally in 1949, Eagle Gorge was recommended to Congress as a site for a dam and reservoir project.

Construction on the dam which included the relocation of 13 miles (21 km) of the Northern Pacific Railway began in February 1959.

During construction in December 1959, the last devastating flood occurred on the Green River; damaging homes and removing topsoil from farms.

The base of the dam is 960 ft (290 m) wide and sits within Eagle Gorge, a ravine with nearly vertical rock walls.

The dam is located within the Tacoma watershed and public access is not allowed, creating controversy among recreation proponents for some time.

Sandbags were distributed throughout the Green River Valley as the USACE continued to inspect, monitor and repair the dam.