SIOUX FALLS, S.D. (AP) — Tim Giago, the founder of the first independently owned Native American newspaper in the United States, has died at age 88, his former wife says.

Giago, who died at Monument Health in Rapid City, South Dakota, on Sunday, created an enduring legacy during more than four decades of work in South Dakota journalism, his colleagues said.

Giago, who founded The Lakota Times with his first wife, Doris Giago, in 1981, was not afraid to challenge those in power and advocate for American Indians, she says. He sold the paper in 1998 and later founded The Lakota Journal and the Native Sun News, based in Rapid City, South Dakota.