Trail Ridge Road in Rocky Mountain National Park, the highest continuous paved road in the United States, opened for the summer season this morning.

The opening, which traditionally takes place on Memorial Day weekend, was scheduled to be marked by a ribbon cutting including the mayors of both Estes Park and Grand Lake, but that event was cancelled due to ice on the road.

The road, which climbs to 12,183 feet, officially closed for the winter on Oct. 17. Last year, it opened for the summer on May 14. The latest it has opened is June 26, in 1943.

Due to heavy melting on the the road during the day, and freezing temperatures at night, visitors to the park should anticipate possible nightly closures. The Alpine Visitor Center and the Trail Ridge Store, perched at 11,796 feet, are expected to open sometime next week.

Park plowing crews started working on clearing the road in mid-April, and encountered snow drifts 18 to 22 feet deep. Much of that snow accumulated in the early spring.

The park staff expects a busy Memorial Day weekend. Both reservation campgrounds in the park are already full for Saturday and Sunday, and the first-come, first-serve campgrounds are expected to also fill up.

Weather conditions in the park can change quickly, and those planning visits can check on conditions there at a recorded phone line, 970-586-1222. For more information on the park, go to www.nps.gov/romo or call the park's information office at 970-586-1206.