Flames illuminate the sky as the East Troublesome Fire burns outside Granby, Colorado, US October 22, 2020 [Jim Urquhart/Reuters]

Authorities in the US state of Colorado have issued an evacuation order for residents near Rocky Mountain National Park, as gusting winds on Saturday fanned the second-largest wildfire in the state’s history.

Officials issued a mandatory evacuation order for eastern Estes Park, a small town in northern Colorado, after wind pushed the 188,300-acre (76,200-hectare) East Troublesome Fire further east.

A red flag warning issued by the National Weather Service was in effect for the area as winds of 97 kilometres per hour (60 miles per hour) and low humidity were expected through Saturday.

“We tried to get ahead of it to get everyone safely out in an orderly fashion,” said Larimer County Sheriff’s Office spokesman David Moore. “We are expecting a very long day. Fingers crossed and prayers.”

A satellite image shows smoke from the East Troublesome wildfire in northern Colorado [Satellite Image 2020 Maxar Technologies/Handout via Reuters]The fire, which started on October 14, was 14 percent contained as of Saturday.

As the flames spread, authorities closed all 668 square kilometres (415 square miles) of Rocky Mountain National Park to visitors and ordered the evacuation of several mountain communities.

The blaze has killed at least two to date, after an elderly couple was found dead in their home outside the town of Grand Lake, about 30km (19 miles) from Estes Park, on Friday.

Grand County Sheriff Brett Schroetlin said Lyle and Marilyn Hileman, both in their 80s, had “refused to evacuate”, instead opting to stay in the home they had lived in for many years.

“Our parents left this world together and on their own terms. They leave a legacy of hard work and determination to overcome – something all of Grand County will need,” the family said in a statement that was read by the sheriff.

Schroetlin called the wildfire “a catastrophic event” in the small community.

Colorado has witnessed the largest fires in its history this year, which has also seen massive blazes in California and the Pacific Northwest of the United States.

More than 1,813sq km (700sq miles) of land have burned so far in the East Troublesome Fire, Larry Helmerick, fire information coordinator for the Rocky Mountain Area Coordination Center, told The Associated Press news agency this week.

Another fire in northern Colorado that began in August and is still spreading – known as the Cameron Peak Fire – has become the largest in state history.

As of Saturday morning, that blaze was 60 percent contained and has destroyed more than 207,000 acres (nearly 84,000 hectares), officials said.

Authorities in Colorado said this week there was a possibility the Cameron Peak Fire and the East Troublesome Fire could merge.

Scientists have pointed to climate change as making wildfires more intense across the US, among other major climate events, such as storms and droughts.

The Cameron Peak Fire, the largest wildfire in Colorado’s history, has destroyed more than 207,000 acres of land [Loveland Fire Rescue Authority/via Reuters]Jennifer Balch, director of the Earth Lab at the University of Colorado, Boulder, said drought intensified the blazes in the state.

She said it is “just a matter of time” until the wildfire threat affects more people, who are moving closer to forests.

“If I had a panic button, I would push it – because we have put millions of homes in harm’s way across the Western US,” Balch told AP news agency.