Rocky Mountain National Park has the highest major highway in the country, which tops out at 12,183 feet above sea level. Nearly one third of the park is above tree line - an elevation of 11,400 feet.
Rocky Mountain National Park holds 72 named peaks above 12,000 feet. Longs Peak (I don't have a picture of it) is 14,259 feet.
Upward earth thrusts pushed the Rockies skyward 70 million years ago. Then, three major glacial episodes sculpted the scenery from 738,000 to 13,750 years ago.