I did not see the route in any of the guide books...
There are 2 older books on just Rocky Butte itself. They were written by Bob Mcgown and occasionally show up at Pows but I am sure the Maz'es have copies in their amazing library..
Bob put way more stuff in that is in PRC. It is likley someone scrubbed out that and many more now dirty cracks.
Heck, the housing development bulldozed in dozens of bolted classics, of course illegally