Below the Dam, Dexter, Mich., postmarked 1910. In this view of Mill creek below the dam, you can see the railroad bridge across the water. The dam was between this bridge and the village.
This card has an RPO from Detroit & Chicago Railroad. RPO stands for Railway Post Office, and was used on cards when they were mailed in the railroad station mailboxes, or handed directly to a railway clerk on a train. Postcards with these marks are much more rare.