I know many kids at both UW and WSU, and a few at Gonzaga, if you are looking for some particulars. I also know a few at Oregon State and my son was recruited by Oregon Tech but never visited.
UW - engineering is higher stress and hard to get into. Frankly, not recommended for him. It takes about a 3.6 at the end of sophomore year to continue in engineering. (Note; UW Bothell does have a small engineering curriculum but is mainly a commuter school).
WSU - A few miles from the Idaho border, so not typically Pacific Northwest, but most of the kids are from “wetside” towns. Lots of spirit and kids tend to love the school, but engineering is still pretty hard. The commute would be bad at break times. Don’t expect any financial aid.
Gonzaga - I don’t know anything about the engineering school though we did look at it for S1. We did look at some sample tests and they seemed in line with what would be typical, not super hard. Except for the athletes we know, the kids there came from strong academic backgrounds.
Oregon State - Again, I only know non-engineering kids, but for the out-of-state ones it has been a mixed bag. Some love it, one hates it, one so-so.
Some others to think about, kind of northwestish but not technically NW, ones my kids considered:
U Idaho, shares a lot in common with WSU and is only 8 miles away;
Montana State, good mix of theory and hands-on;
Boise State, trying hard to become less of a commuter school in a pretty vibrant spot by Idaho standards;
Utah State, no particular reason but it seemed similar in academics to this list;
Wyoming, as the only state college it gets the full gamut, and has oil money.