Firefighters have completed a line all the way around a wildfire that started Tuesday afternoon in west Durango, meaning it is fully contained.

Firefighters spent the day Wednesday “fortifying” the line to ensure no embers escape the burn area, said Chief Hal Doughty, with the Durango Fire Protection District.

The Twin Buttes Fire was mapped at 4 acres in size Tuesday night, up 2 acres based on initial estimates Tuesday afternoon.

About 30 people were working the blaze, including members of the DFPD, wildland firefighters and “half of a hot-shot crew,” or about 10 members, he said. No aviation was expected to be assigned to the fire Wednesday, although a helicopter was on standby if needed, Doughty said.

No smoke was visible Wednesday from downtown Durango, but firefighting equipment was traveling to and from the fire.

The Twin Buttes Fire started about noon Tuesday east of the Twin Buttes subdivision. Firefighters described it as a creeping fire that stayed low and burned through oak brush.

The cause of the blaze is under investigation. Doughty said people were seen near the fire about the time it started, but it is not yet known whether the fire is human-caused or lightning-caused.

“We’ve got evidence-collecting and all that stuff going on,” he said. “The (La Plata County) Sheriff’s Office is cooperating with us on this one.”

The fire has cost “thousands and thousands” of dollars, but local land agencies were working together to share resources to knock down the fire quickly and will determine who pays for what at a later date, he said.

“After today (Wednesday), we should just be able to put it on a watch status and keep checking it throughout the day each day,” Doughty said.

No homes were in immediate danger, and no pre-evacuations had been issued.

Temperatures were expected to be in the mid-90s Wednesday, near record-setting highs for the day.

shane@durangoherald.com