Railpictures.net is pretty awesome for graphical ID on locomotives. You can get pretty much any type of picture of any road, any locomotive on there. It's quite amazing.
Aside from that try googling the road's name and roster after it and you'll come up with something.
CP Rail Roster turns this up:
http://www.trainwe.../cproster/main.htm That's actually a site I've referred to a lot in the past. A complete listing of all numbers, most with photographs in different phases of their lives.