I live in Colorado as well; I'm near Longmont. To be honest, I'm not surprised we've been having so many fires...with all the record breaking hot weather and lack of rain we've had, it's incredibly easy for a fire to get out of control.
I haven't heard that anyone is starting these fires, but I really wouldn't be surprised if it turned out to be true. Probably some pyromaniac trying to make a name for themselves.
Did you hear about the Estes Park fire? They were able to put it out just a few hours after it started, thank goodness. I was really worried that it would spread into town. I just went there with some family a few weeks ago, and it was very beautiful...I'd love to live there some day.