Fort Belknap Indian Community (FBIC)

A sovereign nation comprised of the Aaniiih (Gros Ventre) and Nakoda (Assinibonine) Nations.

Island Mountain Development Group (IMDG)

Created through the FBIC corporate charter, IMDG is an autonomous, for-profit economic development corporation entrusted to serve the FBIC.

Fort Belknap Indian Community Council (FBICC)

FBIC tribal members elect the FBICC. The FBICC protects the health, security, and general welfare of the Fort Belknap Indian Community.

Island Mountain Development Group (IMDG) Board of Directors

The IMDG Board of Directors provides governance, strategic direction, and accountability to IMDG and its subsidiaries.

Empowering Our People

Economic development is the key to breaking the poverty cycle and building strong, healthy, culturally vital Native Communities.

As a sovereign nation, the Fort Belknap Indian Community has the right and responsibility to self-government, including the creation and promotion of economic development to benefit Tribal Members.

A Higher Calling

In 2009, the Fort Belknap Indian Community Council (FBICC) established Island Mountain Development Group (IMDG) as an autonomous for-profit economic development corporation to serve the Aaniiih (Gros Ventre) and Nakoda (Assiniboine) Nations.

IMDG’s mission is to build a self-sustaining local economy through the creation of business opportunities, jobs, and resource development.

Today, IMDG and Tribal Members are working together to bring about true, generational change and economic prosperity to the Fort Belknap Indian Community.

Since inception, IMDG has developed a strategic and viable platform that has enabled continuous growth across multiple business verticals.

Learn more about our investment in key industry sectors

Island Mountain Development Group

Our Values

IMDG embraces and promotes traditional Aaniiih and Nakoda values:

  • Generosity
  • Trust
  • Respect
  • Discipline
  • Patience
  • Sustainability
  • Resilience

4 Pillars of Native Economic Development Decision-Making

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Decision making power resides within IMDG for the benefit of the FBIC.

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Investments and programs must be focused on building a self-sustaining economy on FBIC.

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Cultural Equity

Tribal values including equality, generosity, humility, honesty, respect for resources is embedded in the values of IMDG and reflected in day-to-day business practices.

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Strategic Alignment

Long term objectives and priorities are the criteria by which specific development options are analyzed and business decisions are made.

Historical Timeline

Gros Ventre and Assiniboine Tribes join other tribes in signing Treaty of Fort Laramie, greatly restricting Territorial Lands
Indian Relocation Act – Remaining Tribal Lands Ceded to U.S. Government
Fort Belknap Indian Reservation established by Act of Congress
Current Reservation boundaries established
Tribal Members accept Indian Reorganization Act of 1934
Tribal Members adopt a constitution
Tribal Members adopt corporate charter
Island Mountain Development Group (IMDG) established by Aaniiih (Gros Ventre) and Nakoda (Assiniboine) Tribes 1 employees
IMDG Starts eCommerce Lending – 7 employees
IMDG Operating Revenue $9.1 million – 126 employees
IMDG Operating Revenue $74.3 million 226 employees

Aaniiih (Gros Ventre) and Nakoda (Assiniboine) Tribes

The Fort Belknap Indian Community is home to the Aaniiih and Nakoda Tribes. Both Tribes evolved from a plains Native American culture that relied on buffalo for subsistence and the horse for movement within their traditional territories.

Today, the Tribes have adapted to an ever-changing world and yet retain culturally significant elements that make them distinct as sovereign Nations.

Aaniiih (Gros Ventre)


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Origins, Divisions, Trade

In the mid-18th century, the Gros Ventre acquired horses and at this time experienced their first encounter with the white man in approximately 1754, near the Saskatchewan River. The resulting exposure to smallpox severely reduced their numbers.

In the 19th century, the Gros Ventre joined the Blackfeet Confederacy. After allying with the Blackfeet, the Gros Ventre moved to north-central Montana and southern Canada.

In 1868, the United States government established a trading post called Fort Browning near the mouth of Peoples Creek on the Milk River. While this trading post was originally built for the Gros Ventre and Assiniboine tribes, it was built on a favorite hunting ground of the Sioux Indians, and it was abandoned, as a result in 1871. After the abandonment of Fort Browning, the government built it on the south side of the Milk River, about one mile southwest of the present town of Chinook, Montana.

In 1876, Fort Browning was discontinued and the Gros Ventre and Assiniboine people who were receiving annuities at the post were instructed to go to the agency at Fort Peck and Wolf Point.

The Assiniboine did not object to going to Wolf Point. The Gros Ventre, however, refused make the move knowing they would come into contact with the Sioux, with whom they could not ride together in peace. The Gros Ventre forfeited their annuities rather than make the move to Fort Peck.

In 1878, the Fort Belknap Agency was re-established, and the Gros Ventre, and remaining Assiniboine were again allowed to receive supplies at Fort Belknap. Then in 1888. the Fort Belknap Indian Reservation was established, named for William W. Belknap, who was Secretary of War at that time.

By an act of Congress on May 1, 1888, (Stat., L., XXV, 113), the Blackfeet, Gros Ventre, and Assiniboine tribes ceded 17,500,000 acres of their joint reservation and agreed to live upon three smaller reservations. These are now known as the Blackfoot Confederacy, the Fort Peck Indian Reservation and the Fort Belknap Indian Reservation. By 1904 there were only 535 A’ani tribe members remaining. Since then, the tribe has revived, with a substantial increase in population.

There are currently over 8,000 enrolled members in the Fort Belknap Indian Community, which includes the Assiniboine people, who were historical enemies of the Gros Ventre.

Nakoda (Assiniboine)


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The Assiniboine call themselves Nakoda or Nakota. To the Chippewa, they are known as AS’see’nee pai-tue (those who cook with stones). In Canada, they are called the Stoney, and in the United States they are known as the Assiniboine. Through years of separation, differences in dialect and customs have developed between the two branches of this tribe, however the Assiniboine still remember their common origins, and consider themselves a single people.

Pierre Jean Desmet, a French Jesuit missionary of the early 19th Century stated that the Assiniboine were once members of the Yanktonai band of Dakota (Sioux). The oral tradition of the Assiniboine, however, refutes that claim. According to oral history in all Assiniboine tribal bands, their origins are Algonquin.

Tribal oral history states that the Assiniboine originated in the Lake of the Woods and Lake Winnipeg areas of Canada. The Assiniboine became close allies and trading partners of the Cree, engaging in wars together against the Atsina (=). Together they later fought the Blackfoot.

A Great Plains people, they generally went no further North than the North Saskatchewan River. They purchased European trade goods from the Hudson’s Bay Company through Cree middlemen.

Divisions and Language

In 1744, a division was noted, and “the people” divided again with some bands moving west into the Valleys of the Assiniboine and Saskatchewan Rivers in Canada. Others moved South into the Missouri Valley. Bands also inhabited an area from the White Earth, Minnesota, West to the Sweet Grass Hills of Montana. Some also lived and roamed North of the U.S.-Canadian border to a line running East and West from Hudson Bay to the Rocky Mountains.

There have been thirty-three bands of Assiniboine identified. According to Edwin T. Denig, the Assiniboine returned to the Missouri region between 1800 and 1837, numbering approximately 1,200 at that time.

The Assiniboine language is a dialect of Dakota/Mississippi Valley Siouan language, a subdivision of the Western Siouan language. Ken Ryan, an Assiniboine from the Fort Peck Reservation, used the International Phonetic Alphabet to develop a phonetic Assiniboine alphabet. He found that there are 26 phonemes, 20 consonants, and 6 vowels in the language. Today, about 150 people speak the Assiniboine language (A’ M̆oqazh. The majority of Assiniboine today speak only American English. The 2000 census showed 3,946 tribal members living in the United States.

Game Hunting, Trade, Rituals

The Assiniboine were typically semi-nomadic large game hunters, living in tipis and dependent on the Buffalo, using Buffalo hides for clothing and receptacles. They hunted on horseback with bow and arrow. The tribe is known for its excellent horsemanship. They first obtained Horses by trading with the Blackfeet and the Gros Ventre tribes.

By 1750 the Assiniboine hunting grounds embraced all the Canadian prairies. Both the Canadian and U.S. branches of this tribe occasionally slaughtered entire herds by driving them into compounds. The meat was roasted on spits or boiled in hide bags by means of hot stones. The Assiniboine also made pemmican. The Dog was the only aboriginal domestic animal and was generally used to carry packs and pull travois.

The Assiniboine did a considerable amount of trading with Europeans in the fur trade. They worked with the Mandan, Hidatsa and Arikara tribes.

Most Assiniboine attached great importance to visions, and these took precedence in religious life. Ceremonies and rites were performed individually or in groups, including offerings, prayers, the singing of sacred songs and the solemn unfolding of a pack containing sacred objects. Tremendous importance was attached to the songs, which were repeated according to their mystic number.

The Assiniboine considered sweating necessary purification before participation in any major ceremony. Their favorite incense for major ceremonies was made from sweet grass. Tobacco was, as a rule, reserved for ceremonies and other solemn occasions. The pipes were handed and passed according to definite tribal traditions.

The Assiniboine believed in great power-The Creator. They lived their religion every day. Ceremonial rituals included sacrifices, fasting, and a variety of prayers.



353 Old Hays Rd.
Hays, MT 59527


1537 Avenue D
Billings, MT 59102


1753 U.S. Highway 2 – NW – SPC 36
Havre, MT 59501

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