Walnut Canyon Study Act of 2005 - Directs the Secretary of the Interior and the Secretary of Agriculture to conduct a study of specified Federal land in Coconino National Forest, State and private lands, and Walnut Canyon National Monument in Arizona (the study area) to evaluate: (1) the significance of the public values and resources of the study area as the public values and resources pertain to the management objectives of the Forest Service and the National Park Service (NPS); (2) the opportunities for maintaining existing public uses; and (3) a range of options for managing and conserving resources by the NPS or the Forest Service, or by both agencies, including the feasibility of a boundary adjustment to the Monument, designation of the study area as a national park or preserve, maintaining the study area as managed by the Forest Service, and any other designation or management option that will accomplish the protection of resources and the maintenance public use and access for such area.
Requires the Secretaries to: (1) contract with a third-party consultant with experience in park and land use planning to prepare a draft study; and (2) collaborate with the Forest Supervisor of the Coconino National Forest, the Superintendent of the Flagstaff Area National Monuments, the Flagstaff City Council, and Coconino County Board of Supervisors in developing a scope of work for the draft study under the guidance of the third-party consultant.