The design and implementation of a complete, computerized retrieval system for the engineering and architectural drawings and maps of several large land development firms are discussed. Such collections present unique problems to the cataloger. Each collection is limited in geographic scope to the land owned or developed by the firm; types of maps or drawings vary greatly; and each collection has its own specialized vocabulary and identifiers. Generalized cataloging systems or established subject headings are virtually useless in such highly localized and specialized collections. The problems encountered and the process followed in developing a specialized cataloging system and format, a customized thesaurus, computer software, and managerial procedures for the first system is detailed. The adaptability of this system to other engineering and architectural drawing collections is also discussed. (Author)