Yellowtail Dam

Yellowtail Dam on a cold winter day
Yellowtail Dam on a cold winter day



History and Building of the Yellowtail Dam
By the mid-20th century the Missouri River was notorious for floods that caused millions of dollars worth of damage to cities, towns and farms. It had long been a dream of those who lived near the Missouri River or had interests connected with the waterway, to tame its flood prone waters. This dream became reality in the decades which followed the passage of the Pick-Sloan Flood Control Act of 1944.

Flood control along the Missouri Basin (of which the Bighorn River is a part, since it flows into the Yellowstone which eventually flows into the Missouri) was brought about by the building of a series of over 50 dams and lakes. Prominent among these is the Fort Peck Dam - in northeastern Montana - the largest public works project in American history and the Yellowtail Dam, at the mouth of Bighorn Canyon.

Sixty Years In The Making
Construction of the Yellowtail Dam took place in the 1960s, but the idea of damming the Bighorn had been around since the early 1900s. Irrigation of land for agricultural purposes was seen as a way of helping the Crow Indians to become self-sufficient. Around 1900 the Indian Service (precursor to the Bureau of Indian Affairs agency) began to issue allotments of farmland to the Crow people.

Since the land was in a semi-arid environment, irrigation would be needed in order to create arable land. In addition, the first decade of the 20th century saw hundreds of settlers move into the area, taking up 160 acre farm allotments under the Homestead Act.

The Reclamation Service (precursor to the Bureau of Reclamation) carried out three major studies between 1903 and 1942.

  • An early one recommended a gravity arch dam 480 feet high (the Yellowtail Dam today stands 525 feet high). This would provide irrigation for 60,000 acres.
  • A later study proposed the building of two low dams, one where Yellowtail is today and another about 70 miles upriver near where the town of Kane, Wyoming once stood.
  • In 1950 it was finally decided that building one large dam would be the most efficient idea.

The ground breaking took place in the fall of 1961. A diversion tunnel to reroute the river water during construction was built in the following years. It was approximately 2000 feet long (equivalent to over 6 football fields in length) and 32 feet wide.

On March 16, 1963 the first bucket of cement was poured. Several long years of work ensued, in which there were four fatalities, before the dam was completed in 1967. On October 31, 1968 the dam was dedicated.

The results of the project were hailed as a success, but there were many who adamantly opposed the dam. Ironically, the dam is named after Robert Yellowtail, chairman of the Crow tribe. Yellowtail was firmly against the damming of the river and flooding of the Bighorn Canyon. The Crow people held these lands to be sacred. The dam and river project acquired 12,000 acres of land from the Crow tribe. The agreement specified water rights and assured protection of surrounding areas as their reservation and private property.

The dam was built for the following purposes (priorities listed in order of importance), which have all been successfully met:

  • Flood Control
  • Power Generation
  • Irrigation
  • Recreation

As a result of the Dam, it has been estimated that flood damage was reduced by $113 million between the years of 1965 and 2007. In regards to electrical generation, the Yellowtail Dam is capable of producing up to 250,000 kilowatts of electricity.

The Greatest Impact
Perhaps the greatest impact on the average citizen has been the increased recreational opportunities brought about by the dam. Because the dam regulates the flow of water into the Bighorn, the river has become legendary as a world class trout fishery.

Amazingly, it is now the most fished stream in the state of Montana. The dam also led to the designation of Bighorn Canyon National Recreation Area in 1968. Each year over 200,000 visitors come to enjoy boating, fishing, along with a wide range of outdoor activities.

Last updated: February 24, 2015

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Contact Info

Mailing Address:

Bighorn Canyon National Recreation Area South District Visitor Center
20 US Hwy 14A

Lovell, WY 82431


307 548-5406
(307) 548-5406 is the South District in Lovell, WY. (406) 666-9961 is the North District in Fort Smith, MT.

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