He was a founding board member in 1971 of Sinte Gleska University, the tribal college at the Rosebud Indian Reservation.
[2] After college, Marshall worked primarily as an English teacher at Todd County High School in Mission, South Dakota.
In 1971, Marshall was a founding board member of Sinte Gleska University, the Sicangu Lakota's tribal college located at the reservation.
His most recent role was playing the elder, Loved by the Buffalo, in the Turner Network Television mini-series Into the West.
[3] His works include the following: "In the Footsteps of Crazy Horse" (2015) "Sing For The Red Dress" (2024) He has also written essays based on Lakota culture and collected stories: In 2008, his book, The Day the World Ended at Little Bighorn, won the PEN/Beyond Margins Arts.