If you are spending even just one day in Astoria, you need to visit this place to get a great overview of the town, it's people and it's waterways.
You can spend a great deal of time here if you read all the individual displays. We did not have that luxury but still came away with a boat load of information about the area. Be sure to see the movie as it was a great prelude to the rest of the exhibits.
With a paid admission, one can also tour a lighthouse ship docked nearby. It really makes you appreciate your cozy bed at home.
For all the bad you hear in the news these days, it is refreshing to learn about the folks who brave the Columbia river to make a living and to learn about The Coast Guard crew whose job it is to protect and save them. Highly recommended.