[4] At the age of 10, Westerman was sent to the Wahpeton Boarding School, where he first met Dennis Banks (who as an adult became a leader of the American Indian Movement).

In addition to several solo recordings, Westerman collaborated with Jackson Browne, Willie Nelson, Bonnie Raitt, Harry Belafonte,[3] Joni Mitchell, Kris Kristofferson, and Buffy Sainte-Marie.

Additional film roles include "Chief Ten Bears" in Dances with Wolves (1990), and the "shaman" for the singer Jim Morrison in Oliver Stone's The Doors (1991).

[3] Westerman appeared as Standing Elk, alongside his long-time friend Max Gail, in the family film, Tillamook Treasure (2006).

[3] Television roles included playing "George" on Dharma & Greg, "Uncle Ray" on Walker, Texas Ranger (in the pilot and first regular seasons),[3] "One Who Waits" on Northern Exposure, and multiple appearances as "Albert Hosteen" on The X-Files.