Time is critical-exactly:late for Alaska last year & early this
you just never know.
And when the timing is right, weather may not cooperate. Fortunately, weather is not so much of a problem in Colorado.
Last year for my fall Alaska trip, if I caught the colors on time, I would have been hit by rainy days anyways.
And this year, I was there early and when I left, the weather was going to be nice and so would be the colors. Only problem, the "photographer" has already left.