American Indian Billy Mills, who 20 years ago became the first American to win an Olympic gold in the 10,000 meter run, told a crowd of 300 at the Science Center last night how he was able to triumph in the face of prejudice and opposition.

Mills was at Harvard for the New England premier of a movie based on his life, "Running Brave," which stars Robby Benson as the long-distance runner.

"All my life I was told I could contribute nothing because I was Indian." Mills said in an interview last night. When he won the race in 1964, he told the audience, he asked a race official, "Did I miscount the laps?"

Mills grew up at Pineridge, a Sioux Indian reservation in South Dakota, and was orphaned when he was 12.

He then went to state-supported Indian boarding schools until he won an athletic scholarship to the University of Kansas.

His first exposure to white society was the "most difficult time of my life," Mills said.

"We were taught in the boarding school to be gentle, kind, to treat people as equals: I was so naive when I went to the university," he added.

The $6.5 million movie is the "first to be truly representative of what Indian life is like," the film's producer, Ira Englander, said last night.

A group of Indians in Canada provided financial backing, and Walt Disney Productions is distributing the movie.

Foundation Grant

American Indians at Harvard sponsored the appearance with a $1250 grant from the Harvard Foundation, which supports one event for Native Americans each year.

The group sponsored the event "to give outside people a view of our own group's experience," Joseph D. Bowen '84, a member of the group, said.

Although the student group has sponsored speakers before, Mills' appearance is the first project intended for a wider audience, Bowen said.

S. Allen Counter, director of the Harvard Foundation, presented Mills with an award for his work with Indian youth.

Mills and Englander co-founded the National Leadership Program for American Indian Youth in the seventies.