1916 Montana Steam Locomotive

I run a newspaper in Montana and could use some help researching the history of a steam locomotive..
Recently we were presented with some photos of the "First Train" to arrive in Fairfield, Montana in October, 1916.
(See attached photo)
The locomotive bears the number "2206."
I'm hoping to identify the locomotive and learn about its history for a story.

Thank you!

5 minutes on Google led me to believe that the "CM&SP" on the side of the cab meant "Chicago, Milwaukee and St. Paul Railroad", a.k.a. "The Milwaukee road". The engine is either a 2-6-0 or a 4-6-0 style locomotive. Here's a link to a picture of unit #2200, which looks similar: http://s3.amazonaws.com/rrpa_photos/469 ... 20info.jpg" onclick="window.open(this.href);return false;

If this is the case, it is a 4-6-0 of the Class B type built by Baldwin in the 1890's, and scrapped by the 1920's. If this is 1916, then this is a old locomotive on it's final years, probably fit for use only on lesser branches with smaller freight consists. It was probably pulling a 'work train' used in building the right-of-way. The Milwaukee, of course, fell into bankruptcy over 30 years ago, and very little of it's trackage exists today, since the Great Northern ran pretty much along the same route, and was in much better shape. A route which was once known for rather spectacular vistas on it's passenger trains (such as the Hiawatha) now remains mostly as a rail trail.

I looked up Fairfield, MT in a 1919 Official Guide just to see where it was. It was on a branch from Harlowton, between Lewistown and Great Falls. Other stations on the line were Wachusett, Amherst, Ware, Danvers, Hoosac, Pownal, Waltham, and Salem. Guess who settled that part of Montana? Or maybe did the surveying, if there were no towns yet?