Presented in this thesaurus are keywords and cross references for the indexing and retrieval of outdoor recreation literature. It was compiled to facilitate the development of a common language for outdoor recreation planning, programming, research, and resource management. Terms selected are pertinent to both the natural and physical resources, their value, management, development, and user requirements. The format consists of six sections: (1) alphabetical list of terms with notes showing broader term (BT), narrower term (NT), scope note (SN), preferred term (USE), and UF meaning used for or instead of another term or concept; (2) straight alphabetical listing of terms; (3) display of terms alphabetically within 26 subject categories; (4) grouped array of terms rotated within each of the 26 groups; (5) a rotated array of all terms; and (6) a classified arrangement of terms based on the major categories: (a) Outdoor Recreation Resources and Facilities, (b) Administration, (c) Recreation Activities, Equipment, and Users, (d) Economic Aspects, and (e) Supporting Information. An explanation of sample listings is given together with suggestions for using the thesaurus. (BL)