The "high" part had nothing to do with any 1970's-era drugs. It was all about the elevation! We hiked almost every day, and as soon as we passed 9,000' (2743 meters), I started gasping. I've hiked at elevation a lot over the years. Usually after an hour, I adjust and don't notice. I made it all the way to the top of Kilimanjaro at 19,340' (5894 meters) in 2006. But after five days, still gasping. The hiking was really fun anyway, and the higher you go, the more spectacular the scenery.
And bonus! While I was chatting with the Boy Scouts, Diane spotted an American Three-toed Woodpecker. We didn't get a good look at his toes, but we did clearly see the yellow patch on the top of his head that our volunteer bird walk guide had told us about earlier.
I would say that Rocky Mountain National Park is mainly a hikers' park. Most of it is unroaded, and the many hiking trails access spectacular scenery. But roads ring the edges of the park and the Trail Ridge Road, a high-elevation road with its own spectacular views, cuts through the north of the park. We drove that road twice and took in the views and walked out to the overlooks and stopped for animal sightings along the road.
We did spend a bit of time in town. We carried a picnic lunch with us on a tram ride to the top of a ridge on the edge of town and had lunch with an incredible view.
(If you'd like to see more photos of this visit to Colorado, click here to jump to a Picasa web album of 169 photos.)