I’ve been researching various types of mine tipple structures for my HOn3 Colorado Rockies layout, and have come across two types. There are the type that form a sort of bridge across the tracks, as seen in the Alleghanies, and are the most common type of structure available. The other type is more enclosed, and looks similar to modern grain elevators, with a structure that fits more tightly across the tracks. What I’m asking is, were both types of mines used in Colorado, or would it be one particular type?
With some snooping you should be able to come up with some photos of actual tipples or other mining facilities that actually stood in Colorado during your timeperiod. I started looking in Google under “Colorado Coal Mine”. Here’s a link to one such source:
There were several hundred of what you refer to as “Alleghany” style coal mine tipples in Colorado in the 1890-1930 time period at any given time, in fields throughout the state, some of them lasting until the 1980s such as the Hawksnest Mine at Somerset, Colorado. Coal mining companies, coal mine managers, and coal miners moved to where the jobs and the demand was. Successful practices adopted in one coal field spread immediately to all coal fields. Thus you can work from photos of a coal mine in West Virginia circa 1900 or 1930 and plop it into a Colorado setting and have little worry of being prototypically incorrect. The concrete silos appeared in the late 1970s at coal mines throughout the U.S., including Appalachia.