There are a lot of active divers in the Portland Area.
Many go up on day trips to Hood Canal or Puget Sound on the weekends or even weekdays.
Just about every weekend I head north, but I work at home so I NEED to get out on a regular basis.
Its about a 300 mile round trips -- Leave about 5 to 6 AM - 2 dives back home about 5 PM
Would it be nicer if it was closer sure but its not bad at all.
Connect up with local divers at the Oregon Scuba Club -- www.oregonscuba.com
They are not connected to any one shop in the area -- Divers from all the shops.
Also go check out the various shops around the area and see what local trips they have on the schedule.
There is this weird culture where your almost expected to stay at one shop but I say people should break the mold and visit a bunch of them.
There are a few lakes and rivers in the PDX area you can get your dive on if making a long trek isn't in the cards.
Just ask around and you should be able to find some buddies to do those with you.