YANKTON, S.D. -- Gavins Point Dam may look mighty small when seen in contrast to the size of Lewis and Clark Lake, the body of water the dam holds back.
But a closer look reveals the true enormity, not only of the dam's purpose, but of its physical size.
"I think what really amazes them is the massive size of everything," Karla Zeutenhorst, a park ranger with the U.S. Army Corps of Engineers, said of the reactions of the 15,000-20,000 visitors who annually stop in for a tour of the dam.
A bolt on display in the nearby Lewis and Clark Visitors Center is a good example. The bolt is similar to those used on the turbines that produce electricity in the dam, and it looks more like a tree log you'd sit on around the campfire.
Obviously, water is constantly flowing through the turbines, so visitors touring the dam can't get an up-close look at them, but they do get to see the generator floor, the control room, the high-voltage cable area and the mechanics area, which includes a massive crane used to lift and move machinery in the power plant.
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New power plant lobby displays added this year include a working generator model, a history of dam construction and the mission of the Corps of Engineers, which oversees the dam.
Construction of the dam was authorized under the Pick-Sloan Plan of 1944. Ground was broken May 18, 1952, and the power plant began producing electricity in September 1956. It now produces an annual average of 700 million kilowatt-hours of electricity, enough to meet the needs of 50,000-100,000 homes for a year.
Hydroelectric power production is just one of the dam's purposes, Zeutenhorst said. The dam is also vital for flood control, irrigation, downstream navigation, providing water for municipalities, recreation and environmental stewardship.
Those roles are part of the story told at the visitors center, which sits on a bluff overlooking the dam and lake.
"We tell the story of the Missouri River itself," Zeutenhorst said.
Displays in the visitors center include an interactive map that gives details of the Missouri River drainage basin and the Corps of Engineers' role in managing the river. Other displays inform visitors of the region's early inhabitants and explorers, the fish and wildlife of the river environment, dam construction and the role of the Corp of Engineers in the area. A theater shows movies on the Lewis and Clark expedition, Gavins Point Dam construction and the Missouri River.
There are exhibits of fossils found along the lake and tools and instruments used to build the dam. The visitors center also includes a book and gift shop.
