Tekakwitha Fine Arts Center (Sisseton, South Dakota)
From the web site, the center is "home to the largest collection of Dakota art in the country." 

Joseph N. Nicollet Tower & Interpretive Center (Sisseton, South Dakota)
From the web site, this museum is dedicated to the French map maker, Joseph N. Nicollet, who "spent 1838 and 1839 creating the first accurate map of the vast area between the Mississippi and the Missouri Rivers.  ...His journals also record his love for the prairies, his respect and understanding the Dakota Indian people and his fear about the future for the West that he had come to love." 
 
Turtle Mountain Chippewa Indian Heritage Center (Belcourt, North Dakota)
From the web site, "The goal of the heritage center is to preserve and promote the unique culture and History of the members of the Turtle Mountain Band of Chippewa Indians and their descendants for the benefit of future generations."

The Lakota of the Plains (Carnegie Museum of Natural History)
From the web site, "Through exploration of four different visions of living in and with the natural world--those of the Tlingit of the Northwest Coast, the Hopi of the Southwest, the Iroquois of the Northeast, and the Lakota of the Plains--<this exhibit> examines the belief systems, philosophies, and practical knowledge that guide Indian peoples' interactions with the natural world."  Part of the Carnegie Museum of Natural History's online exhibit,  North, South, East, West: American Indians and the Natural World.

National Museum of the American Indian (Smithsonian Institution)
From the web site, the museum "is dedicated to the preservation, study, and exhibition of the life, languages, literature, history, and arts of Native Americans."

First Peoples Hall of the Canadian Museum of Civilization
This virtual museum contains a wide variety of images and information about the culture of Canada's First Nations.