Drilling crews for lock construction

Photograph showing two drilling crews with drilling apparatus used in blasting ledge rock. Trestle for train used to remove spoils is in the background.
Abstract/Description: Photograph showing two drilling crews with drilling apparatus used in blasting ledge rock. Trestle for train used to remove spoils is in the background.
Subject(s): Boats and boating
Soo Locks (Mich.)
Date Created: 1910 (approximate)