Access to the equipment drawings of the Northern Pacific (NP) and Great Northern (GN) railway companies in the Minnesota Historical Society has been enhanced by the recent availability of two series of index cards. These cards cover parts for freight cars, passenger cars, wreckers, snowplows, and other facilities of the railroads.

The card indexes (ca. 1900-1960s) for the Great Northern Mechanical Department drawings consist of 11 small file boxes of 3×5 cards contained in 3 standard archives boxes. They are grouped according to specific category of parts (air brakes, draft lugs, etc.), tools (repair tracks, air brake tools, piping, etc.), and equipment (box cars, gondolas, ore cars, etc.). The cards reference the specific drawing number for the specific piece of equipment. An inventory providing additional description and the location of the boxes is filed with the Equipment Drawings series in the GN Mechanical Department finding aids notebook.

A similar set of card indexes (ca. 1880s-1960s) for the Northern Pacific Mechanical Department drawings consist of 54 small file boxes of 3×5 cards contained in 9 standard archives boxes. They are grouped according to type of car (box, caboose, flat, ore, hopper, passenger, refrigerator, etc.) or by type of equipment (air brake details, uncoupling levers, heating apparatus, etc.). The cards reference the specific drawing number for the specific piece of equipment. An inventory providing additional description and the location of the boxes is filed with the Equipment Drawings series in the NP Mechanical Department finding aids notebook.

Neither of these specific series of indexes have individual catalog records in MnPALS. They are included in the MnPALS entries for the records of the Northern Pacific Mechanical Dept. and the Great Northern Mechanical Dept.