Abandoned rail line, North of Casper Wyoming

These are photographs of an abandoned rail line north of Casper Wyoming.  I'm unsure of the data on these and will have to research it, but the line itself is long abandoned.  I recall being told that this line, which is quite evident in the locations running north of Casper, was never fully constructed, but I don't know that to be the case.  If true, the construction was quite advanced as can be seen.  I tend to think it was a completed, but abandoned, like running from Casper north to Buffalo and Sheridan.  However, at least as of 1915, it does not appear on the state railroad map.