Here is a video of fish in the fish ladder:
*You can access the Bonneville Dam from either the Washington or Oregon side of the river. Both sides offer views of the powerhouse and fish ladders. The Oregon side has the fish hatchery (salmon) and views of large sturgeon. The Washington side has a nearby self-guided trail.
We actually visited the Washington side of the Bonneville dam, which you access from highway 14. After exiting the highway and traveling back a mile on the access road, we reached the security station for the dam. The person manning the station asked a few questions about firearms and then sent us on our way, with a note that we could not take in large backpacks or purses.
The visitors center on this side of the river is free to visit, and hasn't been updated since it was originally built. It's a trip back in time! After reading a few displays, we headed up the escalator to the area where we could view rows of turbines from above. There were a few more displays up in this part of the visitors center, with information about how electricity is made and sent to homes. There was also a theater showing a movie about Lewis and Clark.
After looking at all there was to see in the powerhouse, we headed down to the fish ladder. Since we were visiting in early April, there were only a few fish making their way through the ladder, but the kids enjoyed checking the fish out.
It's not a fancy visitors center on the WA side, but a worthwhile place for a short stop if you are in the area.
We love taking visitors here and have gone many times. It lets folks get up close and personal with all sorts of salmon. We took our little guy who was only months old, and we were able to get him close enough to the window to see the fish going by. He was following them, so even at that age it was interesting.
You learn about the fish counting (it is basically a person, who sits in a dark room, counting fish all day until someone comes and relieves them). On occasion sea lions make their way up the river and in to the fish ladder (this has been a big problem, and has stirred a lot of controversy when it comes to removing the animals to protect the fish). Kids also get to learn about the life cycles of the fish and what they go through to spawn. There is a neat museum upstairs that talks about Lewis and Clark's expedition and how the Northwest came to be and there is a small exhibit about dams and how power is made with them. There are also locks here, so there is an explanation on how they work as well. Pretty cool!
You have to go through security to get onto the dam (it isn't that big a deal though...you are asked some questions, they check your trunk and underneath the car, and send you on your way).
If you are in Portland or traveling up HWY 84 in the Gorge, this is a really good stop (especially if you need to get out and stretch your legs). It is best to go when the salmon are running too (slightly less to see when they aren't). While you are here, you can also check out the fish hatchery. That is good fun also!