Omer C. Stewart (1908-1991) was Professor Emeritus of the Department of Anthropology at the University of Colorado in Boulder, Colorado and a renowned scholar of indigenous religions, particularly peyotism. He was also an outspoken advocate for the indigenous nations of the United States. Omer C. Stewart and Martha C. Knack wrote a book together in 1984 titled As Long as the River Shall Run: An Ethnohistory of Pyramid Lake Indian Reservation.