One tip I will give when it comes to sun protection is to wear sunscreen and SPF products often. I personally apply foundation, or a SPF BB cream when I leave the house and know I will be outside or even when I am driving for a long time. Also, when I am driving I like to put sunscreen on the top of my hands because during the day the sun will hit your hands as they are on the steering wheel. Your hands are one of the first places that will age fast and gain sun spots. Applying sunscreen on your hands before driving is a simple discipline that over time will save your hands from aging and will protect them from sun damage.
Like I said, I am not an expert… I am not a doctor… However, I hope this post helped to inform you that when in Colorado, or any higher altitude location, it is important to be aware and pro active with your skin protection.