My Mom drove through Albuquerque, NM just last week and told us about an awesome dinosaur/natural science museum that she thought DS (almost 4.5 yo) would love.
I just googled it, and I think it's this one: http://www.nmoca.org/naturalhistory.html
I just googled it, and I think it's this one: http://www.nmoca.org/naturalhistory.html