Over two million acres of open land in northeastern Montana contain rolling hills, prairie, bluffs, and wildlife. This is the Fort Peck Indian Reservation, established in 1888, home to the Assiniboine and Sioux tribes.
The name Fort Peck derives from a former military outpost that once stood on the present-day reservation, a place at the crossroads of culture, commerce, and conflict. With the reservation’s grasslands and the meandering Missouri River cutting through its center, this region was a pivotal backdrop for bison hunts, fur trades, and tribal rituals for centuries, long before settlers arrived.
In this article, we explore the history of the Fort Peck Indian Reservation and life on the reservation today. Learn about reservation politics, society, and culture.

Table of contents:
- Fort Peck Indian Reservation Map
- Quick facts
- History of the Fort Peck Indian Reservation
- Culture and tribes of the Fort Peck Indian Reservation
- Geography of the Fort Peck Indian Reservation
- Economy of the Fort Peck Indian Reservation
- Politics of the Fort Peck Indian Reservation
- Education on the Fort Peck Indian Reservation
- Health on the Fort Peck Indian Reservation
Fort Peck Indian Reservation Map

Quick facts about the Fort Peck Indian Reservation
Below you can find answers to common questions about the Fort Peck Indian Reservation.
What tribes live on the Fort Peck Indian Reservation?
The Fort Peck Indian Reservation is home to the Sioux and Assiniboine Indian Tribes. Each tribe is represented by various bands. The Sioux are represented by the Sisseton/Wahpetons, Teton Hunkpapa, and Yanktonais. The Assiniboine are represented by the Canoe Paddler and Red Bottom bands.
When was Fort Peck Indian Reservation established?
A series of agreements and executive orders throughout the late 19th century ultimately resulted in the creation of the Fort Peck Indian Reservation. An 1873 executive order first established land for multiple tribes at the confluence of the Milk and Missouri Rivers. Later, the Sweetgrass Hills Treaty of 1887 established the official Fort Peck Indian Reservation from a portion of that land. Finally, an 1889 Congressional Act established its current borders.
How big is the Fort Peck Indian Reservation?
The Fort Peck Indian Reservation spans 2,093,318 acres (847,000 ha) in the northeast corner of Montana. The landscape features the rolling plains of the prairie, the Missouri River, and various streams, waterways, and bluffs that are home to coyotes, bobcats, partridges, and other wildlife.

Photo: USDA NRCS
What language is spoken on the Fort Peck Indian Reservation?
The tribes of the Fort Peck Indian Reservation, ie. the Sioux and Assiniboine, speak different dialects of the Siouan language. While their languages are distinct from one another, they are a part of the same language family and share similarities.
Fort Peck Indian Reservation in 200 words
The Fort Peck Indian Reservation, located in northeastern Montana, is home to the Assiniboine and Sioux Tribes. Both tribes speak related Siouan languages and comprise various bands and divisions.
The Sioux are represented by the Sisseton/Wahpetons, the Yanktonais, and the Teton Hunkpapa divisions. The Assiniboine are represented by the Canoe Paddler and Red Bottom bands.
The reservation has approximately 11,786 enrolled members, 6,000 of which reside on the reservation. Enrollment requires a minimum of 1/4 Fort Peck Indian blood, as determined through blood quantum measurements maintained by the tribe.
The reservation spans 2,093,318 acres, of which 926,000 are Indian-owned. This piece of land stretches 110 miles long and 40 miles wide (177 km x 64 km), featuring a mix of tribally owned and Indian-allotted lands.
The population density is highest along the southern border, near the Missouri River and major transportation routes like U.S. Highway 2 and the Amtrak on Burlington Northern Railroad tracks. The Fort Peck Tribes is the largest employer in the region, employing over 350 people.
Brief history of the Fort Peck Indian Reservation
The first notions of the Fort Peck Indian Reservation emerged in the early 1870s as a result of various executive orders by then-President Ulysses S. Grant.
A series of further agreements and executive orders throughout the 1870s and 1880s further established the reservation, reducing it in size as each agreement was made.
Key treaties
Key treaties and agreements that led to the establishment of the Fort Peck Indian Reservation include:
- An 1873 Executive Order by President Grant. This Executive Order established a large territory for multiple tribes, including the Assiniboine, Sioux, Blackfeet, and Gros Ventre.
- An unnamed 1886 treaty. This treaty shrunk the lands of the 1873 Executive Order and established one of the first boundaries around the Fort Peck Indian Reservation.
- Sweetgrass Hills Treaty of 1887. This treaty established boundaries around the Fort Peck Indian Reservation close to what they are today.
- An 1889 Congressional Act. This Act reduced the Fort Peck Indian Reservation to its present-day size with its current borders.
The Fort Peck Indian Agency was established in 1871 to serve the Assiniboine and Sioux Indians as the federal government organized and allocated lands for the tribes of the region.
Originally located within old Fort Peck near the Fort Peck Dam, the Fort Peck Agency was moved to Poplar in 1878 due to annual flooding. This period was marked by U.S. attempts to control the Sioux and other tribes through agencies.

War, strife, and confinement
During the last decades of the 19th century, the region of present-day northern Montana and North and South Dakota was fraught with conflict, namely the Great Sioux War of 1876.
In the 1870s, as gold was discovered in the Black Hills, the U.S. government attempted to annex parts of this region and relocate the Sioux to agencies. While some Sioux agreed, others resisted, becoming known as ‘hostile’ bands. This led to renewed conflict, culminating in the Battle of the Little Bighorn in 1876.
The 1880s saw significant hardship in the region, including the extinction of buffalo by 1881 and a severe starvation crisis by 1884. Over 300 Assiniboine died at the Wolf Point sub-agency due to inadequate food and medical supplies.
The rations the government provided to the reservations were inadequate to meet the tribes’ needs, leading to widespread suffering across the reservation. The situation was worsened by exceptionally harsh winters.

Negotiations in the winter of 1886-87 culminated in the Act of May 1, 1888, which set the contemporary boundaries of the reservation.
Further hardships arrived with the Fort Peck Allotment Act of 1908, which allowed for the survey and allotment of reservation lands, offering 320 acres to each eligible Indian, with surplus lands opened to non-Indian homesteaders.
By 1913, 1,348,408 acres were available for settlement, marking a significant shift in land ownership and use, although not all lands were sold as planned.
Read also: History of the Sioux Tribe
Culture and tribes of the Fort Peck Indian Reservation
The Fort Peck Indian Reservation in northeast Montana boasts a rich and dynamic culture, shaped by the history of the two tribes residing there: the Sioux and the Assiniboine.
Originally close kin in the 16th century, these tribes evolved from allies to adversaries through the 18th and 19th centuries. Eventually, they reunited on the present-day Fort Peck Indian Reservation.
Sioux
The Sioux tribe, known for their hunting and warrior culture, were incredibly strong and courageous.

The tribe is deeply rooted in oral traditions and storytelling, which serve as vital channels for preserving their history, culture, and ancestral wisdom.
They engage in a variety of ceremonies and rituals that reflect their spiritual beliefs and cultural values, including the sun dance, vision quests, and the use of the sweat lodge.
Central to Sioux culture are the principles of bravery, respect, and a profound connection to the land, embodying a lifestyle that promotes harmony with the environment and a strong community bond.
Assiniboine
The Assiniboine, also known as the Nakoda, are known for their large size and their foundational role in the fur trade across the northern United States. They had exceptional skills in horseback riding, which helped solidify their identity as formidable warriors and traders in the northern Great Plains.

Their social organization, spiritual beliefs, and ceremonies are integral to their identity, with storytelling, dance, and music playing significant roles in preserving their history and teachings across generations.
The Assiniboine have a distinct language that is part of the Siouan language family, reflecting their cultural uniqueness and historical ties to other Siouan-speaking tribes.
Learn more: Unveiling the Assiniboine tribe – Lifestyle, tradition, & culture
Geography of the Fort Peck Indian Reservation
The Fort Peck Indian Reservation, located in northeastern Montana, encompasses a diverse and striking landscape that spans over two million acres. It features the endless rolling plains that are characteristic of the entire Great Plains region. The Missouri River forms its southern boundary.
This mighty river provides vital water resources, shapes the reservation’s ecosystem, and offers scenic beauty.
Fort Peck Lake, a man-made reservoir created by the historic Fort Peck Dam on the Missouri River, lies just along the reservation’s southwestern border and supports various recreational activities and wildlife.

The reservation features rugged hills, valleys, waterways, and open grasslands, habitat for various wildlife, including bison, deer, elk, eagles, fox, grouse, osprey, and prairie dogs.
Bison of the Fort Peck Indian Reservation
In 2012, after enduring several legal battles, the Fort Peck Tribes began receiving bison from Yellowstone National Park and reintroduced these creatures to the Great Plains.
Now, Fort Peck Indian Reservation manages over 300 buffalo on 15,000 acres and is the sole Tribal site for the redistribution of Yellowstone bison outside the park.
The reservation has facilitated transfers to 18 other Tribes, Alaska Native communities, and even the Bronx Zoo, and plans to distribute more bison to culturally relevant locations in the future.
Economy of the Fort Peck Indian Reservation
Some of the main sources of income and employment on the Fort Peck Indian Reservation are:
- Manufacturing
- Sewing
- Information technology
- Data conversion
- Production
- Storage
The reservation faces serious challenges related to poverty, unemployment, and education. Consider the following statistics:
- Poverty. According to the U.S. Census Bureau, the poverty rate on the reservation is 34.3%, higher than the state average of 12.1%.
- Unemployment. The latest data I could access indicates an unemployment rate on the reservation of 56.5%, significantly higher than the state average of 3.2%.
- Education. About 92.2% of tribal members have a high school diploma or higher and 18% have a bachelor’s degree or higher, compared to 94.5% and 34.6% for the state, respectively.
Over the past century, the Fort Peck Indian reservation has made significant progress in improving local living conditions and developing economic opportunities for its residents.

Some of these initiatives include:
- Fort Peck Tribal Industrial Park. This is a prosperous industrial park located near Poplar, which is one of the largest employers in the state. It hosts various enterprises, ranging from metal fabrication to electronics manufacturing.
- Hydrogen plant. The tribes are in talks to construct a hydrogen plant to produce fuel for the trucking industry and to create a carbon sequestration site and wind farm.
- Wind turbine. In partnership with local tribes, educational institutions, and utility companies, this project aims to deploy a 660-kW wind turbine on Reservation lands. This initiative will reduce electricity costs with savings allocated towards community and educational programs and employment opportunities.
- Fort Peck Tech Services, Inc. Fort Peck Tech Services, Inc. is a tribally owned manufacturing enterprise offering machining, metal fabrication, and assembly services.
Politics of the Fort Peck Indian Reservation
The tribal government is the Fort Peck Indian Reservation governance structure. The government manages affairs according to its constitution and bylaws. The Assiniboine and Sioux tribes, though distinct, are unified under a single tribal government, known as the Fort Peck Tribes.
Various federal policies and laws have challenged and modified the tribal governing structure over the years. Today, the Fort Peck Tribes is a sovereign nation with its own constitution, flag, and seal.
We summarize the structure and duties of the Executive Board, Tribal Court, and the reservation’s alliances and partnerships below.
Executive Board
The Tribal Executive Board is the governing body of the Fort Peck Tribes, composed of a Chairperson, a Vice-Chairperson, a Sergeant-at-Arms, and twelve board members.
Tribal Court
The Fort Peck Tribal Court operates as the judicial arm of tribal governance, upholding the enforcement of the Fort Peck Tribes’ laws and regulations. The court structure includes a Chief Judge and Associate Judges who preside over civil, criminal, and juvenile cases filed within the reservation’s jurisdiction.
The court is located in the town of Poplar, Montana.

Alliances and partnerships
The Fort Peck Tribes is also a member of the Rocky Mountain Tribal Leaders Council, a coalition of 11 tribes located in the Rocky Mountain region that advocates for tribal rights and interests.
The Fort Peck Tribes are also affiliated with the National Congress of American Indians (NCAI), the oldest and largest organization of tribal governments across the U.S. The NCAI represents the interests of over 500 tribes, advocating for their inherent and legal rights.
Education on the Fort Peck Indian Reservation
Among the key educational facilities is the Fort Peck Community College, located in Poplar. The college offers three associate degree programs: Associate of Arts (AA), Associate of Science (AS), and Associate of Applied Science (AAS).
The college has about 550 enrolled students, of which about 56.4% study full-time. Latest data indicates a graduation rate of about 14.6%.
As we previously mentioned, about 92.2% of Fort Peck tribal members have a high school diploma or higher, while 18% have a bachelor’s degree or higher. State levels are 94.5% and 34.6%, respectively. Public schools on the reservation offer K-12 education.
The Fort Peck Tribes strongly emphasize culturally relevant education, incorporating Assiniboine and Sioux heritage into the curriculum. However, the community continues to face obstacles such as funding limitations and the need for more educational resources to enhance the students’ learning experience.
Health on the Fort Peck Indian Reservation
Health on the Fort Peck Indian Reservation is a complex issue shaped by socio-economic factors, with disparities reflected in the limited access to healthcare resources.
Fort Peck Health Promotion Disease Prevention (HPDP) program
HPDP is one of the reservation’s primary healthcare institutions. They work diligently to provide preventative and primary health services to tribal members, including endocrinology, cardiology, neurology, and respiratory services.

HPDP also offers a telemedicine program as well as school-based services, including suicide prevention, equine-assisted therapy, physical therapy, alternative medicine, chiropractic services, and dental care.
Fort Peck Indian Health Service (IHS)
The Fort Peck Indian Health Service (IHS) is a facility that provides comprehensive and specialized medical care to tribal members. The clinic offers various services, including primary care, dental, nutrition, optometry, and public health nursing.
However, IHS facilities across the country have been chronically underfunded for decades, leading to limited resources and inadequate healthcare for Native communities.
Despite the valiant efforts of programs like HPDP and IHS, chronic conditions like diabetes and heart disease remain prevalent on the Reservation due to both genetic predisposition and lifestyle factors.
There is a pressing need for increased funding and support from the federal government to address the systemic issues facing Native American communities’ healthcare.

