It's been a while since we've done an Ask the Editor. Here's one from the e-mail bag, which lately has been overflowing.
Last February, we had a chance to see the Tehachapi Loop in California. I'm told something similar is here in Colorado between I-70 near Wolcott and Steamboat Springs. How would I find it? Thanks, Ken Harris
Interesting! I think you might be referring to the loops near Bond.
It does not loop over itself, but it does use some significant grade and reversing loops to "cut the contours" or gain elevation. This was part of the Moffat Road beyond the Dotsero Cutoff, which was built by the Rio Grande after they bought up the Denver & Salt Lake Railroad as a means of shortening their Denver to Salt Lake City mileage.
If you hadn't prefaced it with the Wolcott to Steamboat location, I might have just assumed you were being pointed at the Georgetown Loop!⚒