UPDATE - 9:00 p.m. Monday, August 22

It's official. The Colorado Gulch Fire now estimated to be between 15 and 20 acres in size has forced the evacuations of all homes in the Colorado Gulch area.

Spokesman for the Department of Natural Resources and Conservation, Jordan Koppen, told KGVO News the fire was first reported just after 6:30 p.m.

"We have one type three attack helicopter on it, we have three single engine air tanker retardant planes, multiple forest service engines, county and DNRC engines fighting the fire," Koppen said. "At this time the cause of the fire is undetermined, but is under investigation. The fire started in grass but has burned into the timbered area. It's definitely a wake-up call for sure. We're trying to prompt people to get to their local fire department because we're willing to come out and asses your home for defensible space."

Brenda Bassett, Public Information Officer for the Missoula County Sheriff's Office said deputies have gone door to door to let homeowners know of the mandatory evacuations.

"All the residents in the Colorado Gulch area are under mandatory evacuations," Bassett said. "The road spurs off into three different roads. The Rattlesnake Recreation area is also being closed as a precaution. Also, Missoula County Sheriff's Deputies along with fire officials to notify residents in the Starwood Drive area. They're working on a reverse 9-1-1 system that some areas are under mandatory evacuations and some are under a Stage One warning."

Evacuated homeowner and mother of two small children, Robyn Bracken, was notified about the fire while at a much happier event.

"I was at my son's birthday party when one of the gentlemen who was there told me there's a fire up Grant Creek, and I wonder if you're going to be affected," Bracken said. "Before I could even get home to find out, I met my husband on the road, as well as the other evacuees, and he had been told at about 6:30 by the sheriff that it was time to grab your children, and your pets and leave."

Bracken also said her husband was careful to remove any firearms and ammunition to provide a safer environment for firefighters, should the Colorado Gulch fire reach their home.

Bracken spoke of plans she and her husband had been discussing to improve their defensible space, but it hadn't quite happened yet.

"Our house could have a better defensible space,as well as most of our neighbors," she continued. "It is a very heavily wooded neighborhood in Grant Creek. It's not down in the flatland, so I would say most of my neighbors as well as ourselves are sweating bullets right now, because we should probably clear out some of those trees."

A fast moving grass fire that may have started from a power line blown down by the afternoon's strong winds has led to some evacuations in the Grant Creek area.

Assistant Chief Chad Nicholson with the Missoula City Fire Department said the fire may have started from a downed power line.

Grant Creek Road has been closed at Starwood Drive.

"It's preliminary at this point, but we believe the fire was probably started by a downed power line due to the winds that we've been having here," Nicholson said. "Right now, we have the Forest Service, state and the Missoula Rural and City Fire departments are on scene."

Nicholson said some homes have been evacuated due to the advancing fire.

"Just right in the immediate area is where the evacuations are off of LaSalle Way," he said. "We've also got helicopters working and some retardant planes up in the air."

LaSalle Way lies directly between Grant Creek Road and Colorado Gulch.

Nicholson said as of about 7:30 p.m. the fire was at about 10 acres, and putting up a heavy plume of smoke that can be seen throughout Missoula. The interview was cut short when Nicholson received a call to respond to another incident.