Containing the meticulously detailed records of an avid birder, the Coffin journal contains records of sightings, daily logs, and first and last occurrences of birds observed in the years 1912 and 1917-1922, with partial summary data for 1923 and 1924. The records in the journal reflect Coffin's many birding trips in western Massachusetts, mostly in the Connecticut River Valley, however the journal also contains records from the Swift River Valley, the Harvard Forest, the Boston area, and the Connecticut coast. In a few cases, Coffin recorded the numbers of birds observed.