Considering the ODOT map below, I am fairly comfortable counting this as "confirmed," though I have yet to actually check this fragment out in person.
2010 ODOT Trail Plan - Viento - MP 59 - Pg. 29Quatrefoil, Inc., ODOT. The Historic Columbia River Highway: State Trail Plan - Wyeth to Hood River. Winter 2010. (29)
Northern Loop 3a EastboundGoogle Street View
Northern Loop 3a WestboundGoogle Street View
Milepost 59 would have been located somewhere near the east end of the existing CRH fragment...