The Pine Gulch fire, a lightning-sparked blaze raging north of Grand Junction, continued to grow overnight, becoming the fifth largest wildfire in Colorado state history, officials said Thursday.

Burning since July 31, the fire grew more than 16,000 acres, from 51,455 acres Wednesday to 68,323 acres Thursday, according to the Bureau of Land Management. Nearly 750 firefighters continue to battle the blaze, but were unable to make any headway in the face of high heat and gusty winds.

The fire remained 7% contained as of Thursday morning and officials expected it to continue growing. 

“Critically dry fuels, severe drought conditions, critical fire weather creating extreme fire behavior are creating a high resistance to control,” the National Wildfire Coordinating Group posted on its incident website. “Surface fire with group torching and long-range spotting. Fire behavior can be extreme when winds and slope align.”

The Pine Gulch fire continues to ravage timber litter and brush in a sparsely populated area of the Western Slope. Only an abandoned structure has reportedly been burned, but some Garfield County residents have been forced to evacuate, the BLM said.

Temperatures are expected to reach 90 degrees and dry winds blowing up to 27 mph are likely to exacerbate the fire’s spread Thursday, according to the Rocky Mountain Incident Management Team Black. 

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Pine Gulch remains the state’s second highest priority after the Grizzly Creek fire burning outside Glenwood Springs near Interstate 70, said Larry Helmerick, with the Rocky Mountain Area Coordination Center.

The Grizzly Creek fire grew from 3,702 acres Wednesday to 6,251 acres Thursday and is zero percent contained, the BLM said.

Helicopters and air tankers are helping ground crews protect structures as well as preventing the fire from jumping across I-70. The interstate between Glenwood Springs and Gypsum remains closed.

Another fire, the Cameron Peak fire, was reported Thursday west of Fort Collins and north of Rocky Mountain National Park near Chambers Lake in Arapaho and Roosevelt National Forest.

The fire, which broke out around 1:45 p.m., had grown to about 500 acres. Mandatory evacuations for residents and businesses in the area of Colorado 14 have been ordered.

At 6:30 p.m., the Larimer County Sheriff’s Office tweeted that more evacuations are expected and asked people to avoid Poudre Canyon and Red Feather Lakes areas because of the fire danger.

Forty firefighters, two large tankers, four single-engine air tankers, and three helicopters were dispatched to the fire. The aircraft, however, have been grounded by high winds, the Forest Service said. 

This is an ongoing story.