Rule number 1: Bring your WINTER clothing. /forums/images/graemlins/yikes.gif It can snow in The Rockies at any time of the year. The daytime temps can still reach well into the 70's and 80's, but be prepared for cool, if not downright cold nights. I've scraped ice off the windshield in August when camped at around 9,500 feet above sea level. /forums/images/graemlins/eek.gif Keep the warm clothing with you during the day as well. Snow, hail, or cold rain storms can develop quickly over the mountains in the afternoons.
Keep an eye on the sky at all times. Lightning kills several people here in Colorado every summer. When you're up on top of a mountain enjoying the scenery, you become a human lightning rod. If you can hear thunder, even faintly, then you're in danger! One guy got fried here while hiking to the top of Pikes Peak a couple of summers ago. The thunderstorm wasn't even over him yet. Witnesses said that the lightning literally came sideways out of a somewhat distant storm cloud. /forums/images/graemlins/frown.gif The Rockies are incredibly beautiful, but they can be very unforgiving...
Be VERY aware of altitude sickness! Flat landers can get extremely sick from the lack of oxygen. If you start to get severe headaches, feel nauseous, etc., (it's sorta like the worst hangover you've ever had!) then head for lower altitudes. The extra oxygen will help you feel better pretty quickly
Be careful about climbing without proper climbing gear. Most of the mountain rescues that take place in Colorado are to go up and bring down dunces that have free climbed a few hundred feet up and then can't figure out how to get back down. A few of these Darwin Award wannabees even succeed in removing themselves from the gene pool each year. /forums/images/graemlins/eek.gif
There's a LOT of cool stuff to see out west. Just be safe and think before you do something. /forums/images/graemlins/waytogo.gif