Glenwood Canyon is a huge canyon with the Colorado River running through it. The walls of the canyon are red - the color red - which is where Colorado gets its name. The red walls are sandstone with iron in it, giving it it's red color. The rocks are striated horizontally, with lines of green grass, evergreens, and sometimes aspen.
Hanging Lake trail in Glenwood Canyon, 1 hour west of Vail, was the most dramatic trail of our entire week. It is a steep 1.2-mile ascent to a beautiful waterfall and lake, positioned halfway up the red-walled Glenwood Canyon. Absolutely gorgeous! Take plenty of water and wear good boots. It takes from 30 minutes for the young and hearty to 1 1/4 hours for the people like me who are out of shape and not used to elevations of 6,000 to 7,000 feet.
Grizzly Creek trail, also in Glenwood Canyon, is an easy trail running along a white-water creek. In June, the water - snow melt - was pounding powerfully on the rocks, making for dramatic scenes and wonderful sounds. Wildflowers along the path were both alpine and desert flowers, plus wild coral bells, astilbe, wild rose, violets, columbine (Colorado's state flower), solomon seal, holly, etc.
The smells and sounds along Grizzly Creek are wonderful: the smells of wild flowers and shrubs blooming, the sounds of birds singing, and the creek crashing along rocks.
Take a backpack if you plan to be out more than an hour. We had a rain shower every afternoon. It is hard to tell what the weather will do, since you can only see part of the sky--the rest being blocked by mountains. Take water--about 16 oz. per hour--and wear boots, as the trails are rocky. Bring a poncho for rain and a jacket for cold. On June 3, one and a half hours into our hike, the sky turned dark, and we had a thunder and lightening hail storm! It was quite chilly, and I was glad to put on my long-sleeve shirt, plus my T-shirt, plus my jacket, all under the poncho, which kept me dry.