Interlockers in Delta County

The following sources are utilized in this website. [SOURCE-YEAR-MMDD-PG]:

• [AAB| = All Aboard!, by Willis Dunbar, Eerdmans Publishing, Grand Rapids ©1969.
• [AAN] = Alpena Argus newspaper.
• [AARQJ] = American Association of Railroads Quiz Jr. pamphlet. © 1956
• [AATHA] = Ann Arbor Railroad Technical and Historical Association newsletter "The Double A"
• [AB] = Information provided at Michigan History Conference from Andrew Bailey, Port Huron, MI