The original highway was slightly North of the current one. There are still short sections of it there. It had to be a scary drive in it's day.
It is interesting that they are using horse drawn rail carts on a track to move dirt.
Notice how the tracks were narrowed between them allowing the horses to walk with out stepping on the iron rails.
...looking at the hillside in the background rules out Bugby loops. But it could be lower down towards the mill.
Ken Hellweg, I agree with you as this photo being just down hill from the beginning of the loops.
This could be on the way up to Clatsop Crest in the background. The height of the ridgelines are roughly the same... Doesn't look like one of the loops; nothing matches. It can't be Loop 2 or 4. Loop 1 out of the question, as is Loop 3.