I don't know about Portland but I grew up in Seattle-Tacoma area and Bay Area rap has been popular there ever since I remember.. My first experience with Bay Area rap, not counting MC Hammer, was when I was about 6 or 7 and I stole my older cousins "Spice-1 - 187 Proof" cassette tape and also I remember having a blank tape with the N2Deep album on it around the same time.. Think the same cousin made me the tape.. Rappin 4 Tay, E-40, Luniz, Too Short, Mac Dre, EA Ski are names I remember hearing music from in from elementary school.. And in high school you was kinda like a "cool kid" if you listened to Bay Area rap.. I was in high school in the 2000s but a lot of people I went to school with listened to 90s Bay Area (especially Vallejo) and Sacramento rap I know I knew multiple people with Black Market Greatest Hits, Xorcist, The Rompalation, Young Lay and that first Dubee album.. I think part of the reason is because Bay Area rappers tour in the Northwest while most major rappers will only hit LA and maybe the Bay on the west coast.. Every concert I have been to in Seattle or Portland was Bay Area rappers or Sac rappers other than Devin The Dude.. Also think the black culture in Seattle Tacoma and Portland area is similar to Bay probably cause many people move up from the Bay id say the way we talk and dress is more similar to the Bay than to LA, NYC, Atlanta or any other regions