Lemme see your Wyes!! Wyes used to be prevalent anywhere a turntable was not located, and an engine needed turned. These wye tracks used to be located in helper districts, yards, etc. Here's one to get us started: Blossburg, MT at the summit of the Continental Divide at Mullan Pass:
Not the best shot of it, but the three AC's are on the Mojave wye. The top end of the Mojave Yard wye keeps going, and becomes the Oak Creek branch. Thom
Elk Park Wye The Elk Park Wye just south of Silverton on the D&RGW narrow gauge. The locomotive is about to cross the switch for the north leg. The south leg can be seen behind the train heading away from the river.
I suppose it was used primarily for turning the power on MOW specials and snow plows. There was a siding a quarter mile north on the main line where a train could be parked while the engine could be pulled off of either end and turned on the wye to take the train back the way it came. It is also a flag stop for back packers getting on and off.
From my recent D&SNG trip During the winter operations, which lasted until the early 1950's, it was not uncommon for snow slides to block the tracks at Elk Park. The wye enabled locomotives to turn and pull their trains back to Durango.