Series: Photographs
Physical Description: 97 prints and 70 negatives 
Scope and Content Note: Images of Wisconsin tunnels (including abandonments) mainly of the Chicago, Milwaukee, St. Paul and Pacific railroad (CMStP&P), C&NW, and IC railways made by Kaysen, May 1964 - May 1975. Also included is a negative and print of the CMStP&P tunnel at La Farge, summer 1929.
Arrangement of the Materials: Currently arranged by year (Mr. Kaysen's arrangement); most of the prints and negatives have identifying information written on them.