This photo, taken from the Gambo Bridge looking north up the Presumpscot River, shows a wooden dam and control gate, and two of the mill buildings owned by the Oriental Powder Mills. The Mills produced 25 percent of the Union gunpowder during the Civil War.

Charcoal for the gunpowder was produced in the two buildings, which sit on a small island, and were part of a much larger complex. The logs in the river were not used by the powder mill; likely they were left from log drives destined for the S. D. Warren Paper Company in Westbrook.

Oriental Powder Mills got its wood for charcoal production from the surrounding forest.