- Colorado National Monument, Grand Junction, nps.gov/colm: Cyclists will feel this route in their lungs and their legs. Rim Rock Drive is steep with 2,300 feet of elevation gain over a 33-mile loop. Bikes must be equipped with lights.
- Cottonwood Pass, Buena Vista, bit.ly/1oJAIRR: While this climb ranks among the state's finer routes, it's the descent that sets it apart. From a launching point above 12,000 feet, the descent is all about speed with many straightaways.
- Hoosier Pass, Breckenridge: tinyurl.com/krqsuhe, Stunning vistas, steep grades, sharp turns and smooth highway - this ride has it all. But it also has traffic, and plenty of it. The highlight is the final 4 miles to the summit.
- Pikes Peak Highway, Cascade, visitcos.com/pikes-peak-cycling: This one is steep, challenging and one-of-a-kind. You'll need $12 to get through the tollgate. Don't forget a few extra bucks to buy doughnuts at the summit house.
- Trail Ridge Road, Estes Park, nps.gov/romo: This is a classic mountain ride through Rocky Mountain National Park. The road is smooth. The climbing is difficult. And the vistas are stunning.
Nathan Van Dyne, The Gazette