How long do you spend in the museum?

You can easily spend 3-4 hours there, especially with the consideration of the Smithsonian section! There's a docent tour of the Alaska section which I would highly recommend. Times change but the tour that I took was at 1pm. We visited in the morning around 10:30am but had to go back after lunch as we really wanted to study the incredible Smithsonian section.

I think we stayed less than two hrs. But my kids aren't old enough to appreciate the whole museum.