By Jennifer McRae

RIO BLANCO COUNTY, Colo. (CBS4) – The largest fire burning in Colorado on Wednesday is the Oil Springs Fire in Rio Blanco County. The wildfire grew substantially on Wednesday to 11,933 acres.

It’s not contained.

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(credit: Rio Blanco County Sheriff’s Office)

Multiple agencies are battling the fire, located about 20 miles south of Rangely near the Colorado-Utah border.

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Oil Springs Fire (credit: Rio Blanco Sheriff)

Fire crews say the fire burned through the night along Highway 139. That highway remains closed, but the fire has not crossed to the east side of the highway.

Firefighters set up sprinkler systems around the Dragon Trail oil and gas infrastructure along County Road 116. The sprinklers are fed by portable water tanks and pumps. The portable tanks are refilled by water tenders.

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Oil Springs Fire (credit: Rio Blanco Sheriff)

Lightning caused the fire on June 18.

Jennifer McRae