The Municipal Street Railway System annual reports date from 1919 to 1937, although reports for some years are missing. Two reports exist for 1919; the second is a report on the finances of the Municipal Street Railway System by the Comptroller. The reports include financial information (in its first year of operation, the System operated at a loss of 18,000 dollars) and information on routes, including schedule changes and revenue, as well as other operating statistics.

Correspondence of A.W. Pierce, Superintendent of Railway.

Miscellaneous reports and studies relating to the Municipal Street Railway System including audits, traffic counts, rider volumes, and the 1939 Beeler report on efficiency and cost-effectiveness.

Instruction memoranda to employees relating to schedule changes, policies and procedures, etc. Includes bulletins of the Seattle Electric Company.

Records from a committee reviewing the municipal street railway system as it faced a large monetary shortfall.

Correspondence, memoranda, notes, and studies relating to planning, routing, rehabilitation of the system, and trackage and equipment. These are the files of M.D Anderberg.

Correspondence and contracts for purchase of equipment, capital improvements, land acquisitions and extension of track. Includes some material from the Seattle Electric Company.

Drawings, cost estimates, correspondence, photographs, and copies of ordinances relating to purchases of equipment, laying track, and constructing facilities.

Correspondence, drawings, cost estimates, and photographs relating to the removal of street railway tracks and sale of equipment.

Property and equipment appraisals for the Seattle and Rainier Valley Railroad which became part of the City's railway system.