I have recently been looking at old newspapers at the Library of Congress website. Chiefly Canon City, CO and Miles City, MT. One thing I was wondering about was cities like these (rather than the smaller places) and the prices of goods in the 1870s-1890s and how those changed when railroads came and such. I think these both got railroads in the early 1880s?
And besides prices, of course, how did wages change? Doesn't have to be for these places, specifically -other cities in the then-west in the time frame would be good, too.
The arrival of rail service could have a profound effect of the economy of a Western town. I do not have specific information about Colorado or Montana, but I have studied and published on the issues associated with rail service to Virginia City/Gold Hill and the Comstock Mining District of Nevada.
The transcontinental RR, of course, connected the coasts in 1869. Unemployed Chinese American work gangs were immediately hired by the Virginia and Truckee RR to connect to the transcontinental in Reno, and then passing through Carson City, then passing along the Carson River, and up to Gold Hill and Virginia City. The connection with Gold Hill was secured in late 1869. The difficult connection to Virginia City was secured in 1872.
As a result of the railroad, the number of employed teamsters was reduced by more than half. The transportation of goods dramatically decreased. Most importantly for a mining district, the transportation of ore became extremely easy and cost-effective. This meant that poorer quality ores were suddenly "viable": they could be transported to mills (in this case along the Carson River) at a much reduced rate, so ore with less gold and silver could be milled profitably. This also caused the extinction of Ophir City and contributed to the demise of Washoe City, both of which had depended largely on ore-processing mills, serviced by teamsters.
Besides teamsters, I can't say that I have observed an effect on wages generally as a result of the RR. An archaeological "signature" of the arrival of the railroad was in the form of oyster shells: before 1869, one could only find Pacific Coast oysters, shipped as quickly from the coast by teamsters. These oysters were round and small compared to the oysters of the Chesapeake Bay (and elsewhere on the Atlantic Coast). Atlantic oysters were oblong and much larger. Though more desirable, before 1869 they could only arrive shelled and canned. After 1869, fresh Chesapeake Bay oysters in their distinctive shell, began arriving by the tens of thousands. They represented many feet of deposition in the local dump, and they can be used to date a site.