Vine Deloria Jr. (March 26, 1933 – November 13, 2005) was a Hunkpapa Lakota scholar, author, historian, and activist. For samples of his writings see Spirit and Reason: The Vine Delolria, Jr. Reader. These two interviews are some of his most thoughtful and critical reflections on spirituality and native people.
Follow this link for an article I wrote while discussing Native American religions with Vine at the University of Colorado, Boulder.