Did the SOO Line own a rotary snow plow? - Trains Magazine

Besides the already mentioned Jull plow (The X-18 built in 1892 and scrapped in April 1935), the Soo Line owned several Leslie style rotaries. 

There was the X-16 which was built by Cooke in 1888 and scrapped in November 1938, the already mentioned X-17 that was built by Cooke in 1907 and scrapped in November 1965, and one of four Lima built plows constructed in 1949/1950 which was numbered the X-19 and was scrapped in March 1966.

The X-19 in fact was the 2nd to last new-build Leslie style rotary plow in this country by a commercial builder (William Bros. built three of a new type of rotary plow after the winter of 1949/1950). Rock Island's Lima shows a January 1950 build date versus the December 1949 date for the Soo plow, and construction numbers show the Soo plow with a higher number than Union Pacific's pair. 

The Lima's timing was poor. Diesel rotaries were just about to come into vogue, yet these were expensive and modern steam rotaries that had decades of life left in them. So far older sisters went to the front of the line for rebuilding and dieselization/electrification.

By the time the Lima's were some of the last Class 1 steam survivors and logically would've gone in for reconstruction, already mentioned right of way improvements had decreased the need. So rather than rebuild, they were retired without replacement.