The "original sheet music" in the Erie Canal website that you linked is dated 1913. It could be different from the text by Allen, 1905.
Allen was a tin pan alley composer; he seems to have had no working experience with the canal.

A transcription purporting to be from 1905 has 15 miles.

I'll hedge my bet, but I still want to see the 1905 printing before I throw in my hand.