Rocky Mountain National Park closed as wildfire explodes across Colorado

Officials closed Rocky Mountain National Park to visitors Thursday after a wildfire exploded across Colorado and forecasters predicted more dangerous fire conditions across the region.

The park, which spans the Continental Divide and is one of the most visited national parks in the country, was closed after the blaze — known as the East Troublesome Fire — burned across 100,000 acres Wednesday, incident commander Noel Livingston said in a briefing Thursday morning.

An afternoon briefing was canceled because of an evacuation order, officials said. Mandatory evacuations were also ordered Thursday in parts of Estes Park, a town of 6,000 in the Rocky Mountains, while hundreds of residents in the small town of Grand Lake were also forced to evacuate Wednesday.

The fire jumped the Continental Divide and burned into the west side of the park.

Jimmy Negri, a former helicopter pilot for NBC affiliate KUSA of Denver who owns a cabin in the Grand Lake area, was forced to flee Wednesday night. He described the fire as "a whole new territory."

On Wednesday morning, he told the station, the blaze was 14 miles away. Just before 7 p.m., he got an alert to leave immediately.

"As we were driving out, it was right next to the road," he said.

Speaking overnight, Grand County Sheriff Brett Schroetlin told residents that he usually has a message to deliver "when I choose to speak with you."

"Tonight, I'm not even sure what those words are," he said. "Today has been an extremely, extremely challenging day.

"We never expected 6,000 acres per hour to come upon our community," he said, adding that he didn't know what authorities would find left of the area when they surveyed the damage in the morning.

The fire, which started a week ago, had grown to more than 125,000 acres by Thursday and was only 5 percent contained. Livingston said dead and damaged trees destroyed by pine beetles and hot, windy weather were driving the fire. Officials were expecting another day of potentially explosive growth.

"It's going to be a long day for the firefighters," Livingston said.

North of the East Troublesome Fire, Colorado's largest wildfire on record, the Cameron Peak Fire, was still burning across more than 200,000 acres, while in Northern California, residents were on alert with a "red flag warning" in effect through Friday.

A staggering 4.1 million acres have burned this year in the state. Experts and officials have attributed the record season to climate change and a buildup of dead and parched wildland vegetation that acts as fuel for the fires.