The Soo Line rostered 45 GP9 locomotives, delivered between 1954 and 1957 as part of an order of EMD, Alco, and FM locomotives to complete the dieselization of the railroad. The GP9 fleet included 15 units equipped for passenger service, supplementing 14 previously delivered FP7 locomotives to completely dieselize passenger service. 

The Soo Line had a reputation for excellent locomotive maintenance, and these locomotives could be found working across the railroad up to the time they were sold to the I&M Rail Link (IMRL) in 1997. The IMRL was a new regional railroad created to operate former Milwaukee Road lines in Illinois, Iowa, Minnesota, and Missouri sold by the Soo in 1997. This 1,300 mile regional was acquired by the Dakoka Minnesota & Eastern in 2002 and operated as the Iowa, Chicago, and Eastern Railroad (ICE).

The passenger service of the Soo Line is well preserved with multiple passenger cars, steam locomotives, and 2 surviving F-units. However, I thought that the last remaining passenger service GP9s were lost to scrappers when the Canadian Pacific sold the last of the GP9s on the ICE to scrappers in the early 2010s. 

I was amazed to see this October, 2022 photo on railpictures.net of two former Soo GP9 passenger-service locomotives, still in I&M Rail Link markings, awaiting a call to service at the Farmers Co-Op of Hanska in New Ulm, MN. 
https://railpictures.net/photo/819097/

These locomotives are

GP9, builders number 20114, Frame Number 5371-7, built January, 1955.

The Soo Line Historical Society identifies this as a Phase I GP9

Delivered as Minneapolis, St. Paul and Sault Ste. Marie Railroad (Soo) 556

Later carrying renumbered to Soo 4321, IMRL 123, and ICE 123

Other photos of this locomotive may be viewed here:
http://www.rrpicturearchives.net/serial ... 14&mfg=EMD



GP9, builders number 21437, Frame Number 5439-1, built May, 1956

The Soo Line Historical Society identifies this as a Phase II GP9

Delivered as Minneapolis, St. Paul and Sault Ste. Marie Railroad (Soo) 557

Later carrying renumbered to Soo 4232, IMRL 124, and ICE 124

Other photos of this locomotive may be viewed here: http://www.rrpicturearchives.net/serial ... 37&mfg=EMD

A photo of Soo 557 leading the Laker out of Chicago’s Grand Central Station in June 1962 may be found among this gallery of Soo Line passenger trains: https://www.trains.com/ctr/photos-video ... e-gallery/


Additional information may be found in: Johnson, Rick and Kleckhefer, Guy N. "Invincible Warriors: Soo Line's GP9's." The SOO: The Magazine of the Soo Line Historical and Technical Society. Vol. 19, No. 2, Spring 1997, p 14-29

Are there other Soo Line GP9s remaining in industrial or short-line service?

ILSX 1332 should still be at the Farmers Cooperative elevator in Lidgerwood, North Dakota. She's the former CPR #8263, originally Soo #2404. One of the handful of Soo GP9's retained by Canadian Pacific and rebuilt by CPR in the late 1990's (Which were the last capital rebuilds of 1st generation Geeps on a Class 1, I believe).

I believe the others that CPR did (three of them, iirc) have all been scrapped. At least one of them was used as trade-in credit in the late 2000's on a new GP20C-ECO, with her truck frames and a few other miscellaneous components reused on the otherwise new locomotive in order to save a few dollars and to enable her to only have to meet Tier 0 as rebuilt power (Reminiscent of all those FT's that were "rebuilt" back in the day into GP30's and such, except this time it was all about the emission levels that the locomotive had to meet instead of tax savings by rebuilding instead of purchasing new).