From the NPS website:
Cyclists Should Expect Extremely Rough Road Conditions Due To Major Roadwork On Trail Ridge Road in Rocky Mountain National Park During this summer and possibly the summer of 2011, a major resurfacing project is taking place on a 19 mile section of Trail Ridge Road in Rocky Mountain National Park from the Colorado River Trailhead to Rainbow Curve. This project will also involve resurfacing of all major overlook parking areas, pull offs and the parking lot at Alpine Visitor Center.
Park visitors can expect 20 to 30 minute delays through the construction area on Trail Ridge Road. There may be multiple areas of construction occurring concurrently, and in that case the combined delay time will not exceed 60 minutes. There may be some temporary night closures as well, which will likely occur sometime after mid-July. Work will not take place on weekends or holidays. Cyclists and motorcyclists should expect extremely rough road conditions throughout the summer. Because weather conditions may change rapidly, park visitors should be prepared to adjust travel plans accordingly and are encouraged to call the park’s Trail Ridge Road recorded phone line at (970) 586-1222 for the current status of the road. Park staff will update the recorded line during and after regular office hours, when the road status changes. For further information about Rocky Mountain National Park please contact the park information office at (970) 586-1206 or check the park’s website at www.nps.gov/romo.