Records mainly about state water projects and sometimes federal reclamation and interstate water projects as they affected Wyoming. The files often include correspondence to and from natural resource board officials, the state engineer's office, governor, and Wyoming Congressmen and federal officials. Also included are reports, maps, newspaper articles, and photographs.

*Many of the records date from when the Natural Resource Board was in existence. For reference purposes pre-1951 records may be found in the files. Although the board was abolished in 1969, some post 1969 records have been kept to document the completion of a project.