Only about a decade prior to this, the Ann Arbor would not be passing a switch to exit their yard and enter mainline trackage, however, through a track agreement with Grand Trunk Western, the AA was able to eliminate its track from just outside of Durand all the way back to San Yard and utilize GTW trackage on the Holly Sub to the Grand Rapids Sub. To this day, even though the GTW tracks are operated by Huron and Eastern and the AA tracks are operated by Great Lakes Central, the arrangement is still the same. 35mm slide from my collection, photo by Bob Wilt.