Of the 15 players you listed the only "Washington or Northwest" kids that got meaningful minutes and were recruited by GU were Heytvelt and Gray. Micah Downs was a McDonalds AA who went to Kansas and never was recruited by GU... He transfered to GU to be closer to his GF.
The remaining players that got meaningful minutes: Pargo, Brown, Bouldin, Daye, Gibbs, and Goodsen were all from out of the area.
My point is that GU has been consistently recruiting outside of the Pacific Northwest for over 2 decades and does NOT simply rely on local kids as you have infered.