As a Washington resident it pains me to say Oregon has anything better than Washington, but I prefer the Oregon side because there is a wider variety of things to see (fish ponds with giant sturgeon and salmon just across the glass and at eye level, the boat locks, mature shade trees and a nicer area, a better gift shop, hatchery etc.) Washington side is better only when salmon are migrating and you can go down to glass fronted viewing area and see them swimming up the fish ladder.

We went to the Oregon visitor center, but it sounded like there was more opportunity at the Washington one. We were told you could tour on the Washington side. It is also newer. We drove back to Portland airport by way of Washington side and it was a beautiful drive.

The U.S. Army Corp of Engineers operates and maintains the Bonneville Lock and Dam. The phone number for further information is 541-374-8442.

Bonneville Dam has a fish count that is available online. This will help you keep track. I can't put the link here, but you can find it in the "Columbian" newspaper from Vancouver, WA.