Jantzen Beach RV Park
Jantzen Beach RV Park 1503 N Hayden Island Dr
Portland, OR 97217 - 8285
We rented a space there for a month last year when we worked on the National Figure Skating Championships. They have nice laundry and shower facilities, and a pool during the summer months.
If you don't need your car everyday, there are good connections. It's about a 10-block walk to the Tri-Met bus line, a few minutes on the bus to the MAX line, and a direct train to downtown.