All real estate is local. The last housing market crash was very unique because it seemed to influence housing markets across the entire nation. I don't think we will ever see that again.
I think the Denver market is a bubble because wages are not keeping pace with the cost of housing. Boulder is not a bubble because wages have kept pace with the cost of housing. Even though the cost of housing in Boulder (800K) is more than twice the amount of Denver (400K), I would consider Boulder to be more stable and less of a bubble.