Dotsero is the junction between the Rio Grande's Tennessee Pass line and the Dotsero Cutoff, which connects to the old Denver & Salt Lake? Moffat Route at Bond. It also marks the confluence of the Eagle and Colorado Rivers, which form the two water-level routes that the Tennessee Pass and Dotsero Cutoff lines follow, respectively.
The Tennessee Pass line arrived at what would become Dotsero in 1887, as a result of the extension being built to reach the mining boom at Aspen?. This would be standard gauged in 1890 and continue to serve as the Rio Grande's primary mainline across the Rockies until the Dotsero Cutoff was completed in the summer of 1934.
An oft-quoted story is that the name "Dotsero" is really a corruption of "Dot Zero", referring to it as the origin point of surveys of the Dotsero Cutoff. This is almost certainly false, as Dotsero existed on Grande timetables back at least to 1902 - long before the cutoff was even contemplated.
As a point of trivia, it's also the closest that the Rio Grande's lines come to a volcano. Located northwest of the junction, the Dotsero Volcano last erupted around ~4200 years ago.
Maps and Photos
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