Transformative Consequences of Garrison Dam: Land, People, and the Practice of Archaeology

Dam building is a major human endeavor. The World Register of Dams currently lists 58,266 “large dams,” defined as those measuring over fifteen meters in height.¹ Smaller dams are not included in the register, but in aggregate, small reservoirs are estimated to have three or four times as much total surface area as large dam reservoirs. Global estimates for reservoir area vary, ranging between 400,000 km2 (estimated in 1993) and 1,500,000 km2 (estimated in 2000).² The United States, with 9,265 large dams, is the second most dammed country in the world (After China’s 23,842 and followed by India’s 5,102).³ Including smaller dams, the total for the United States adds up to some 75,000 dams. All US watersheds larger than 2,000 square kilometers have one or more dams altering their flow.⁴

Garrison Dam in North Dakota (Fig. 1) is one of many large dams built in the United States during the mid-twentieth century. This essay examines the history and impact of Garrison Dam and its reservoir, Lake Sakakawea. The focus is historical issues related to dam construction, as well as the environmental and social impacts of large dams in general and of Garrison Dam in particular. Most importantly, included is an investigation as to how archaeology in North America was influenced by the construction of Garrison Dam and the other large dams on the Upper Missouri River.

The Construction of Garrison Dam—A Federal Affair

Garrison Dam, built between 1946 and 1952, is an example of a modern dam. Dam building, irrigation, and hydropower have been practiced for thousands of years. The extensively researched Jawa dams in present-day Jordan date to approximately 3000 bce and are often cited as the oldest known dams, although archaeological evidence of irrigation canals in the foothills of the Zagros Mountains in Iran is potentially associated with even earlier dam-building activities.⁵ Structures built to divert rivers for irrigation or water storage existed throughout the Middle East and Egypt in the second and third millennium bce, and spread throughout the Mediterranean and Europe during the Greek and Roman periods.⁶ Technologies for converting flowing water into mechanical energy date back almost equally far.⁷

Fig 1.

Map of Garrison Dam and Lake Sakakawea on the Missouri River in North Dakota (based on data from Google).

Archaeological evidence of dam building also exists in the Far East as well as the Americas.⁸ Dams in the Americas long preceded the arrival of Europeans. The Chimu Empire of the Andean highlands (in present-day Peru) constructed dams, as did the Maya in the northern part of the Yucatan Peninsula.⁹ The Hohokam constructed elaborate irrigation networks in what is now the state of Arizona.¹⁰

Modern-era dam construction proliferated with the industrial revolution as bigger industries needed more water power, and growing urban areas needed a larger water supply. Dams grew ever larger, but until the twentieth century there was little scientific understanding of dam engineering and thus there were frequent collapses and other failures.¹¹

In the nineteenth-century United States, there were many dams built for municipal use, industrial power, and irrigation by local governments or collectives of water users. This changed in the twentieth century, when the federal government became the dominant dam builder.¹² Two agencies were primarily in charge of building the large dams of the twentieth century: the US Army Corps of Engineers and the Bureau of Reclamation.

The US Army Corps of Engineers was established shortly After US independence. From the beginning there was a push for the Corps to do “works of a civil nature” in addition to military construction. In 1816, mobilization studies based on data from the War of 1812 concluded that national defense would benefit from improved rivers, harbors, and transportation systems, allowing for faster troop movement and logistics...