After graduating high school, he worked as a fire lookout in Yellowstone National Park for 12 weeks, later crediting the solitary post as giving him "time to think about the environment".
[2][4] Disillusioned by government work due to what he believed were improper concessions being given to United States Senator Clifford Hansen, who grazed his cattle in the park, Shanks resigned from his job at the NPS.
At Utah State, he spoke extensively against the Sagebrush Rebellion, asserting that the movement was motivated by private interests and big business, and not a sense of patriotism as supporters claimed.
[1] Shanks subsequently served as director of planning for the Arizona parks department and as policy advisor on land management issues in the office of the governor of California.
Dan McDonald, the Republican majority leader in the state senate, signaled his support for Shanks as did a coalition of 16 conservation groups, including the Audubon Society.
[7] Reporting on Shanks' resignation, the AP's David Ammons wrote that he had a "reputation as a fierce advocate for dwindling fish and wildlife stock ... [that] pitted him against user groups, particularly commercial fishermen".
[2][12] As of 2024, he is a member of the board of directors of the Resource Renewal Institute, which describes itself as advocating "for the conservation, preservation, and restoration of our public lands for current and future generations".
[2] In a 1985 article for Sports Illustrated chronicling a ski trip with Shanks and Governor of Arizona Bruce Babbitt, Kenny Moore described him as a "mild, wry man".