The major portion of this subseries consists of correspondence from the Olmsted Brothers regarding the planning and development of the system of parks and boulevards in Seattle. Subject matter also includes the Alaska-Yukon-Pacific Exposition, the Olmsteds’ ideas regarding responsibilities of a Parks Superintendent, the hiring of J.W. Thompson as superintendent, and John C. Olmsted’s trips to Seattle.

In addition to correspondence, the records include agreements, news articles and clippings, brochures, drawings, expense accounts, plan index cards (photocopies), reports, and Don Sherwood's notes and essays. The photocopies of the plan index cards, which were obtained from Olmsted Associates, Inc., include the subject, scale, and date of Seattle parks and facilities drawings that the firm has on file.