To echo some of Chris' earlier comments, these fires have been around for tens of thousands of years and will likely continue to exist after we're gone. I don'y know the details of the natural ecosystem, but I suspect that un-natural management by humans has caused the problem to skew so far to one extreem. Many ecosystems require periodic pruning by mother nature via burns. Without them, the balance is upset. I would suspect that the bark beetle infestation boomed becasue there are so many adult trees near the same age for a large area. Normally, smaller pruning fires would likely have caused adult stands to be more of a patchwork quilt, separated by previously burned areas of open or young, healthy trees. Our efforts to create a picture perfect forest, or to develop forest management techniques (better describes as crop harvesting technigue), tend to run counter to what the natural ecosystem desires and throughs the balance out of whack. Unfortunately for the folks effected, mother nature has a way of ensuring balance in the long run.