 Tinker is the Clifford Baldridge Professor of American Indian Cultures and Religious Traditions at the Iliff School of Theology in Denver, Colorado, where he has taught since 1985.He is an ordained Lutheran pastor of Living Waters Episcopal/Lutheran Indian Ministry in Denver.Tinker is a member of the Osage Nation, and is also on the leadership council of the American Indian Movement of Colorado and director of the Four Winds American Survival Project.