...definitely a "shoe-fly" or detour route to keep 30 open while the contractors blew up the hillside to make the big cut for the 1954 'modern' highway. I've verified about 1,000 feet of it with asphalt underneath all of it. This was probably used from about 1952 through 1954-1956.
The orange line is the temp road. It leaves newer 30 on the west side and then met up with the old road after going over the top. I'd like to have you and Stephen on the same trip and the good legs can climb over this large dirt pile (20-ish feet high) at the end of the old road at the road cut. This is where we observed the highest level of road fracturing too.
I swear I have PTSD from my attempt on the shoe-fly!
I just need to spend about 4 hours with my weed eater to cut a good path up the shoe fly. But I have a feeling ODOT blew a small piece of it to sever it when the modern highway opened. I'll know at some point, maybe even this Winter.