Just found this next to the Horse Ridge Research Natural Area on Google Maps a little southeast of Bend on Hwy 20. Looks like a few miles of abandoned highway. [Map above]
I'm surprised it's not some kinda drag strip by now. Looks to be in pretty good shape. The southern end connects to a dirt/gravel road that reconnects with hwy 20.
Just for something to call it, I named it after the geology / historical marker nearby on modern US 20.