The volumes in the Proprietors of Locks and Canals on the Merrimack River Collection are more than an assemblage of antiquarian books but a self-contained library with its own system of classification and call numbers. Located in a separate area from the collection resides the analog card catalog, housed in a wooden cabinet, appearing to be fully intact. The cards are a combination of cursive entries and typed descriptions, organized by subject. This custom built system combines letters and numbers, "A1" being the first entry and "Y179" the last. The numbers are inked on the spines of the books and the verso of the front boards of each volume. In some cases, the nomenclature previous systems of organization has been redacted.
15 linear feet of the collection (54 monographs) have been entered into WorldCat with "Proprietors of Locks and Canals Collection" used as both a bibliographic note and as a tag. In order to preserve the original shelf arrangement native call numbers are used rather than Library of Congress.