During the time of the Northwestern (1903 - 1914) there were four loco's on the roster.
Number 4 was sold to BW & SSM in 1901 from CPR, having been built in Taunton, Mass by William Mason for the New Brunswick Railway. It may have been renumbered to 64 under the NW system. Along with #65 she was scrapped in 1913.
Number 65 was built in 1883 for Midland Railway by Manchester Locomotive Works, was aquired in 1903 and scrapped in 1913. This picture is believed to be from 1903, just after the purchase.
Number 66 was the first of two bought new from Locomotive and Machine Company, (later named the Montreal Locomotive Works) in 1904. Scrapped in 1922.
Number 67 was the second of the two new engines. Aquired in 1906, when this picture was taken, it didn't take long before she had mounted a set of antlers above the head light.