Correspondence, estimates, contracts, specifications, drawings, reports, photographs, lists of various bridges by division, and other miscellaneous bridge related material, mainly from 1880 to 1916.

Eighteen notebooks containing notes about bridge structures and conditions, as well as maintenance and repairs performed, at various dates.

A variety of record books related to bridge construction and grade revisions, including volumes containing final reports, construction progress photos, drawings, and engineering data, mostly from the 1920s.

Correspondence, reports, maps, and other materials related to bridges, viaducts, trestles, turntables, coaling stations and coal docks, water tanks, gravel pits, tunnels, and concrete, cinder, and rail reclaiming plants, mostly 1910s-1950s.

Annual reports, by division, of bridges and culverts. A summary of the system is included with the Eastern or St. Paul volumes. From 1892 to 1915 reports were made June 30th. 1916 has both a June 30th and December 31st report. Thereafter the reports were made December 31st.

Details include the type of structure; number, spans, and lineal feet in existence at the beginning of a year; new structures; old replaced; and number in existence at end of year. Reports for 1928 were not located.

The first box of this series, 138.F.8.6, contains a volume which includes the following information: Bridge number, milepost location, class, kind of foundation, truss, pile or trestle, culverts, length, distance top of tie to bed of stream, plan number, stringers, ties, date built, cost, and remarks. There are also some bridge drawings included (Form 126).

The rest of the boxes in this series, 138.F.8.7-138.F.9.4, contain monthly statement of bridges and culverts constructed by division from 1934-1959 (Form 124-A).

This is a series of journals, ledgers, distribution books, and other records of accounting matters in the Engineer's Department. It dates chiefly from 1880-1890 and predates much of the Chief Engineer's Material Book series and the Distribution Record series, although it documents similar expenses. Some of the records pertain to construction costs of a particular branch line or improvement; however, most of the records are summary documents and are arranged according to division or state. Other records describe such costs as surveyor's camp expenses, General Office Building expenses, and contracts and estimates.

This series of records documents the costs of constructing Northern Pacific lines. The Engineering Department used the Distribution Records with a corresponding series of Material Books to account for costs of materials, equipment, and labor.

Each expenditure is entered under a single account. In many instances the accounts in a Distribution Record are divided among six categories: Engineering Expenses, Land, Roadway, Track, Structures, and Miscellaneous. The number of accounts in a category varies from 1 to 15 depending on the nature of the work undertaken by the Engineering Department. Indexes or lists of accounts are attached to the inside covers of most of the Distribution Records.

Many of the records pertain to branch lines and extensions. A few records document structures such as bridges, station houses, and tie plants.

This series of engineering records documents the costs of constructing Northern Pacific lines from Superior, Wisconsin to Puget Sound. The books are field records and include daily entries of expenditures for materials, equipment, and labor. Costs of rails and ties, grading and other engineering work, tools, lumber, office supplies, meals, salaries, and transportation are among the expenditures listed in the books.

Most of the books pertain to rail lines and rail beds; however, the books occasionally include expenditures for such structures as bridges, station houses, docks, and tie plants. The series chiefly documents the costs of branch tracks and extensions rather than the main line.

The Chief Engineer's Old Vault Files contain information, circa 1867-1890s, related to the construction of Northern Pacific main and branch lines from Wisconsin to the west coast. Also included are construction department materials on the building of bridges and shops, the General Office Buildings at St. Paul and Tacoma, and occasional depots.

Types of materials include annual reports of the Chief Engineer's department and of its geographical divisions, surveys, contracts, estimates, proposals, specifications, drawings, payrolls and other financial records, and occasional items related to other departments, such as summaries of rolling stock. Many of the files are related to branch lines, including such items as articles of incorporation