It's impressive to find photographs of a post office that was only in operation for four (4) years. It's even more impressive to note that this post office was at one time considered to be the highest post office in the WORLD.
Here are two side-by-side illustrations of the Waldorf, CO post office. Note the photo on the left is a dated photograph illustration from 1909; the postcard on the right suggests that the post office was located down one building further than that shown on the photograph. While it may be possible the post office relocated to the building next door in the four years it was operating, it appears the postcard shows someone "inking in" the words "POST OFFICE" on the building, so I am inclined to believe that the photograph more accurately illustrates the location of the post office.
In any event, it's an interesting comparison. As one website put it, this was not a town where people
lived; but rather a mining town where people
worked, so it was short-lived when the mining work and the railroad relocated.

Here's another period photo:
