Johnson was born in Detroit in 1958. He is of African-American and Native American ancestry. While living in Germany, where his father was stationed in the Army, Shelton, at five years of age, went on a family vacation to the Berchtesgaden area in Germany’s Bavarian Alps, which later became the Berchtesgaden National Park. He describes this visit as influential in developing his awe for mountains and the sky. His family also visited the Black Forest. Johnson graduated from Cass Technical High School in 1976. He attended college at the University of Michigan, where he graduated with a B.A. degree in English literature in 1981.He next served with the Peace Corps as an English teacher in Liberia. He later returned to the University of Michigan to do graduate study in poetry before going to work for the National Park Service.