LARIMER COUNTY, Colo. — A fire that began when a prescribed burn got out of control Wednesday is now fully contained, according to a Friday update from the Larimer County Sheriff's Office (LCSO).

About 50 homes were threatened by the Elk Fire, which burned south of County Road 74E, north of Elkhorn Road and West of Rim Road -- an area southwest of Red Feather Lakes and about 38 miles northwest of Fort Collins. 

All of those evacuation orders were lifted Friday.

The Sheriff's Office said new mapping provided a better estimate of the fire's size. Officials said it burned 622 acres, which includes 472 acres inside the prescribed burn area and an additional 150 acres of wildfire.

A shed was damaged, firefighters said. No one was injured. 

Evacuation notices went to 904 devices in the area. An alert sent out by the LCSO Wednesday evening said: "Evacuate the area immediately and as quickly as possible. Do not delay leaving to gather belongings or make efforts to protect your home or business. Evacuating immediately not only supports your safety, but also allows emergency crews better access to the area."

The LCSO announced earlier that emergency personnel would be conducting a prescribed burn near the Glacier View Meadows subdivision Oct. 15 - Oct. 18.

The LCSO said it was contacted around 4 p.m. Wednesday by the Nature Conservancy, which was conducting the prescribed burn that was supposed to cover about 500 acres. The group said they burned about 350 Tuesday, and Wednesday the burn got out of control.

The Nature Conservancy released the following statement about the fire: 

"This week The Nature Conservancy was conducting a prescribed fire at the Ben Delatour Scout Ranch near Red Feather Lakes, CO. We are working to get more details, but we understand that a wildfire has been declared. Larimer County Sheriff's Department in now managing the fire and we are fully cooperating with authorities and supporting their efforts to contain it. We are in touch with Larimer County. Of course our highest priority is the safety of the firefighters and local community. We are grateful for the efforts of all local law enforcement and fire professionals."

Several people wondered why a prescribed burn - essentially, fighting fire with fire - was allowed in the first place if conditions were dry. 

WATCH: Why was a prescribed burn allowed when conditions were dry?

A prescribed burn is a method of preventing large wildfires in the future by burning back overgrown forest today. That was the goal of the Nature Conservancy when they scheduled this prescribed burn.

One burn manager 9NEWS talked to, who is not associated with the Elk Fire, said that if there is a Red Flag warning, it usually prevents a prescribed burn from happening.

In this case, there was not a Red Flag Warning issued in Larimer County this week. The weather remained just short of the criteria for a warning. There were warm and windy conditions, and the ground is extremely dry, but that is also part of the reason prescribed burns are so important in the first place.

The LCSO said that they will be looking into the decision-making process with this prescribed burn, to see if anything could have been done better.

A spokesperson for the U.S. Forest Service said the burn near Glacier View is separate from a prescribed burn their personnel have been conducting north of Red Feather Lakes, and that operations there continue to go well. 

RELATED: Grass fire burns more than 500 acres near Red Feather Lakes

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