The assessment of the mineral resource potential of the Routt National Forest and the Middle Park Ranger District of the Arapaho National Forest, Colorado, was conducted so that the mineral resources of the forest can be considered along with other resources in land use planning. This report discusses the potential for as yet undiscovered mineral and energy resources within the forest. Mineral resource information is given in terms of mineral deposit types and their geologic settings, and mineral deposit types are defined by geologic characteristics of known deposits that may occur within or near the forest. All available information regarding mineral deposits or occurrences and energy resources, as of June 1994, was assembled to assess the mineral and energy potential. Geologic maps were compiled and mineral and energy potential maps were also created for deposit types within the forest.