A tractor with a disk trailer rolls toward the Substation Fire on its way to cut fire lines just off state Highway 197 south of The Dalles on Tuesday. Gov. Kate Brown has invoked an emergency order in response to the wildfire.

This story has been updated.

Six firefighters from Union County, all of whom responded on virtually a moment’s notice, have stepped forward to help combat the 50,000-acre Substation Fire in The Dalles area.

The firefighters arrived on the scene in Wasco County on Wednesday and are now working 6 p.m. to 6 a.m. shifts. The firefighters are J.B. Brock, Justin Hughes and Nate Harden of the La Grande Rural Fire Department; James Petty of the La Grande Fire Department and Forrest Warren and Justin Clark of the Imbler Rural Fire Department. Five of the six are volunteer firefighters.

“They are giving up their time for the cause. Hats off to them,” said La Grande Rural Fire Chief Larry Wooldridge.

The firefighters’ departments each provided a brush fire truck, which can carry 300 to 500 gallons of water.

The six firefighters volunteered their help Wednesday after Wooldridge received a call from the State Fire Marshal’s office. Wooldridge was asked if Union County had people available to help with the Substation Fire. Wooldridge put the word out and by 3 p.m. the six firefighters were bound for Wasco County. They began fighting the blaze Wednesday night.

“They are securing the line on the southern edge of the fire,” Wooldridge said.

The six Union County firefighters teamed with five Umatilla County firefighters to form a Strike Force unit for the Substation blaze. Fire departments in Umatilla County contributed a brush truck and a tender truck for the Strike Force.

Imbler Fire Chief Mike Barry said the blaze is particularly challenging because it is wind driven in an environment with low humidity and high heat, giving it it volatility.

“Wind-driven fires have high flame lengths and move fast,” he explained.

See complete story in Friday’s Observer