Great for kids! As we were getting ready to leave our car and go inside we decided to bring a few things to keep our 3 year old enterained while we walked through and read about history. Other natural history museums we've been to have only been somewhat accommodating to children of his age. As soon as we got to the first exhibit, he wanted to jump right out of his stroller and see all the great pictures and do some of the activities. The only time he returned to his stroller was when we were leaving.
There a few exhibits you probably aren't supposed to touch but there are plenty that could keep you occupied for some time. (Panning for gold, any of the many puzzles on the floor and the excavation pit). The day we went we were right in the middle of our Arizona road trip seeing a few historical sites and this museum really brought some of those sites together and even answered a few questions the hosts at the sites couldn't answer.
We really enjoyed our time here and recommend this museum to people of all ages.