In Portland, don't miss:
- Powell's BookStore (probably the best in the country)
- the rose garden, and take the narrow-gauge train to the
- Portland Zoo.
Before leaving the Portland area, drive east along the Columbia River on I84 toward the Dalles, and oogle the many falls, especially
Multnomah Falls. Stop in Hood River for lunch, and then watch the wind surfer - best spot in the country for that sport.
Also - check on Lassen Peak to make sure it's hikeable. They're rebuilding the trail, and some days it's closed. I was there a week or so ago, and had no problems. Look on the NPS website and if necessary, call them.