The Southern Manitoba Railway (reporting mark: SMNR) was formed in 1999 to operate several ex-CN branchlines in Manitoba, Canada. The SMNR was an affiliate of the Tulare Valley Railroad Company of Salt Lake City, Utah and was owned by Kern W. Schumacher. On August 22, 1999 they took over the operation of the following CN subdivisions:
- CN Miami subdivision, mile 2.01 near Morris to mile 62.1 (Somerset)
- CN Carman subdivision, mile 78.9 (Somerset) to mile 118.8 (Belmont)
- CN Hartney subdivision, mile 0.0 (Belmont) to mile 41.0 (Elgin)
Initial power included ex CN engines 3518 (M-420(W)) and 3536 (HR412(W)).
The entire Hartney subdivision, as well as the track between Mariapolis and Belmont, were removed some time before 2007.
In April 2006 the SMNR asked the Manitoba Motor Transport Board for permission to discontinue service between Morris and Mariapolis (ref: Branchline May 2006, p.15), citing reduced grain tonnage. Despite the potential purchase of the Mariapolis elevator by Canada Malting (ref: Branchline July 2006, p.16), the Motor Transport Board approved the abandonment of the line on January 19, 2007 (ref: Branchline, April 2007, p.13)
CANDO Contracting began removing track in the summer of 2007, and by late summer 2008 only 14 miles of track remained west of Morris (ref: Branchline October 2008, pp.18-19).