"That's what Emmett is all about," Joan Quinn Eastman said.
He will also be running in memory of his friend Floyd "Red Crow" Westerman, who died from leukemia complications in December. Westerman, a Dakota musician and activist, also played the character Ten Bears in the movie "Dances with Wolves."
When the race is over, the 76-year-old will rejoin the Longest Walk II, a group that is crossing America on foot asking that sacred American Indian sites be protected.
It is Emmett Eastman's fourth transcontinental journey, having participated in one before the 1996 Olympics to promote American Indian health and culture, one to draw attention to national conservation efforts, and one to have the Olympic medals of American Indian Jim Thorpe reinstated after he was stripped of his amateur status years earlier.