We stopped in on a rainy day and spent about an hour & a half going through their various displays. It's only $5 per adult, and worth a visit. The lady at the front desk was very nice and gave us an overview of the museum so we'd know our way around. I'm not sure how often they change themed displays, but when we visited they had 4 themed sections set up: local brewing & info on Prohibition in the area, influential women of Clark County, local music, and the waterfront/naval shipping.
Our only disappointment was many of the displays consisted of nice printed placards/signs with information for you to read and photos printed on them, with some actual objects and a few photos for you to view. It was truly a lot of reading. Don't get me wrong, it was all very interesting, but I'd like to see more actual objects/artifacts to see in person, or replicas, with some signage to go along with it rather than mostly signs. But it was still worth of visit, and nice to learn more about the local history since we're relatively new to the area.
They also have a research library in the basement you can access (I'm not sure what the fees are). They do ask that you make an appointment to access the research library. read more