A member of the Leech Lake Band of Ojibwe, she volunteered with the Native American Rights Fund and worked for the reestablishment of the Menominee Indian Reservation.

Her family was poor, living on a subsistence diet in a one-room cabin next to Lake Winnibigoshish in Bena.

[1][2] When she was a young child, two social workers made an unsuccessful and illegal attempt to remove her from her family.

[1] In Washington, D.C., Treuer worked for the reestablishment of the Menominee Indian Reservation alongside Silvia Wilbur and Ada Deer.

She was a lawyer for Red Lake schools[5] and a contract tribal judge for the Bois Forte Band of Chippewa in the 1980s.

[1] Margaret met Robert Treuer (d. 2016), an Austrian immigrant and Holocaust survivor, on the Red Lake Indian Reservation.