I believe that one leg of the wye was someplace over near the row of small cabins (or whatever they were) at the base of the hill. Probably whipped out by the cabins and/or the roadway in front of them. Some place I've seen a photo of a distant view of an engine turning on the wye.
Between the road to the Nevada DOT yard and the summit the present highway appears to cross the right-of-way twice. Then a little higher up on the north side (and straighter) is the grade of either the next-generation-back, older highway or a construction detour.
BN