On envelope: "Amity Canal, Culvert W. Br. Horse Cr. #148 - Old line of canal before construction of culvert began July 15, 1907, #149 - Same, #150-1-2-3 Excavating with fresno cable and hoist engine July 29, '07, #154-5 Concrete work Aug 1907". First two images show men and a woman on old canal bank. Images three through six show workers digging canal using a fresno scraper powered by a cable and hoist engine rather than horses. The West Branch Horse Creek mentioned here is a small branch of Wild Horse Creek in Prowers County, Colorado.