Winds of 20 to 30 mph pushed the Picnic Rock Fire into an menacing inferno Thursday afternoon, expanding to 3,500 acres.

Firefighters have been working for two days to contain the raging wildfire that continues to blaze a crooked and orange path up the mouth of Poudre Canyon, creeping ever closer to two mountain subdivisions, and prompting the mandatory evacuation of more than 100 people.

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The wind-fed blaze grew all day Thursday, and had "very active burning," moving north, northeast, authorities said.

"We just have the right combination of dry pine fuel, winds blowing the right direction, and that is making it a tough fire to get a handle on, especially this early in the season," said Steven Hall, a fire spokesman.

One home and one garage along Obenchain Road have been lost, the Larimer County Sheriff's Office confirmed at a public meeting held for evacuees Thursday night.

Twenty-three homes and 70 outbuildings are threatened. The fire is currently 15 percent contained. A 30 percent containment is expected overnight.

The fire is growing toward Highway 287, and the north end is about a half-mile from the Bonner Peak subdivision.

Automated calls were placed to 128 homes in that subdivision and along Obenchain Road Thursday, urging residents to evacuate. They had been warned that a mandatory evacuation order could occur at any moment.

"We did use an emergency phone notification message last night to the folks in Bonner Peak around 5:30 telling them be ready, you're on alert, get everything going because you may have to leave in a hurry sometime today," said Eloise Campanella, with the Larimer County Sheriff's Office, Thursday morning.

People in the town of Livermore, north of the fire, and in the Cherokee Hills subdivision are also evacuating, although they have not been ordered to do so, 7NEWS reported.

A daytime Red Cross shelter for evacuees was set up at the LaPorte Prebyterian Church, 3820 N. Hwy. 287 in LaPorte. The Red Cross evening shelter for those who need a place to sleep is less than a half-mile east of that location at Cache La Poudre Junior High School. The Larimer County Animal Response Team is on standby at the church to help out with livestock evacuation issues.

Those living closest to the fire reside near the Obenchain Draw Drainage, authorities said. Evacuees who live in that area are not being allowed back in their homes after they leave.

The southern end of the fire is the section that appears most in control.

"We'd like for it not to move to the northeast just because there are access and terrain issues and it would make fighting it over there more difficult," said Jason Mantas with the Poudre Fire Authority.

Overnight winds gusting to 35 mph fueled the fire Wednesday evening, causing it to double in size and forcing authorities to call in 120 more firefighters to help.

Resources Stretched, Conditions Tough

More than 220 people are currently working on this fire. Two heavy 800-gallon air tankers, two single-engine airtankers and two Type III helicopters and four 20-person hand crews are dispatched. More hand crews and more Type I and II equipment have been requested. At least one of these crews is made up of prisoners, 7NEWS reported.

Dry thunderstorms, shifting winds and low humidity are all slowing down the battle to fully contain the blaze.

"Winds are very erratic here and that's the problem up here. You never know which way it's coming from or which way it's going. It's very, very dry. The terrain is something to worry about, where firefighters have to watch out to make sure they are safe. And I understand that their communications system is not completely up and running today. So they need to relay messages up and down so we're concerned about that," Campanella said.

"The storm's coming and the winds will come up and it could be a real mess because that stuff starts blowing and you never know what'll happen," said Spur Canyon resident Wendell Franks.

A cold front is expected to move in late Thursday or early Friday, but there is a concern for high winds Thursday night.

Authorities say firefighter safety remains the No. 1 priority. A Type II management crew, experienced in handling large fires, took command of the firefighting efforts Thursday.

The Federal Emergency Management Agency on Thursday also approved federal assistance for fighting the Picnic Fire, which means that FEMA will cover 75 percent of the cost of fire suppression.

The blaze forced the closure of Colorado 14 -- west of U.S. 287 and to Stove Prairie Road -- because the fire loosened rocks along a hillside and sent them tumbling on to the road, fire information officer Tammy Williams said.

Alleged Fire Starter To Face Charges?

The fire started Tuesday at about 11:15 a.m. when a resident lost control of a burning trash pile behind his home.

Anthony Sanchez told 7NEWS the fire started when a spark from a pile of trash blew into dry grass several feet away.

"(The fire) was still in our yard when we called (for firefighters). By the time they got here, it was way up the hill," Sanchez told reporters.

"If there's anybody out there listening, just don't burn. Even if it's a little burn and you think you got it under control, you never get it under control," he said.

Investigators say Sanchez did not have the required permit for an open fire. Sanchez said he did not know he needed a permit.

The Larimer County Sheriff's Office said Sanchez will most likely face charges for setting a fire in the woods or prairie, but it is not known exactly what the charges will be. He could also be held responsible for the costs of fighting the fire.

The estimated cost of fighting the fire has already totaled more than $220,000. A single slurry drop costs $5,000, 7NEWS reported.

Authorities said the investigation to determine the exact charges is taking a back seat until crews can get a handle on the fire.

Resources from all over the country have been requested because local authorities aren't prepared for such an early fire season.

"The resources are not even in place yet. And that's the problem. This is so early for fire season. That's one thing. They started the briefing this morning asking the firefighters, 'What month is this?' You would think this would be July or August, not March," said Campanella.

The official start of the fire season is still a month away. Colorado remains mired in a drought with no sign of relief.

"This is a bad sign for this time of the year, and we have to take this as a warning that we could have a potentially long year, an extreme year," said Justin Dombrowski, Boulder's wildlands fire manager.