Perhaps nowhere--at least not in the last 40 years--is the idea of railroading in Colorado more realized than
Tennessee Pass. A former narrow gauge route surveyed as a way to reach the riches of Leadville's mines and supply them, punched through the summit with a tunnel bore and classic lopsided profile of 1.7% grade on one side and 3% on the other, Tennessee Pass runs right through the heart of the state and until the Union Pacific merger in 1996, served with distinction as the highest mainline in the nation.
A whopping ten units on Tennessee Pass pull and shove their coal train up 3% grade at Mitchell, Colorado, September 5, 1995. With new AC4400CW and
two manned helper sets, Mr. Danneman says, "This was Tennessee Pass at SP’s best!" It's hard to disagree, Mike.◊
PS: For those interested, Fred Frailey (one of the best) writes about the
Long Autumn of Tennessee Pass in his blog at
Trains magazine (2012).