A large grass fire has been contained north of Douglas, and no injuries have been reported nor structures destroyed, Converse County Sheriff Clint Becker said Friday afternoon.

"They're (firefighting crews) are going to be out there for quite a while mopping up, but unless the wind does something crazy, they've got it under control at this time," Becker said.

Emergency responders received the call about the fire at 10:29 a.m., he said.

"We've got eight Douglas fire trucks out there, a couple of Glenrock trucks, a few rural fire trucks, (county) road and bridge, and some oil field equipment as well," he said.

The cause of the fire is unknown, Becker said.

Some structures on a ranch were threatened but they were not damaged, he said.

As of 3 p.m., the fire was traveling south towards Highland Loop County Road west of Wyoming Highway 59 about 27 miles north of Douglas, Becker said.

That's where the fire was stopped. That road is closed.

It is about several square miles in size, he said. "We don't have an estimate at this time."

The firefighting crews will stay on the scene as long as necessary, but the cold weather can affect water flow in the equipment, Becker said.

"It's just a little bit difficult time of the year because the water situation can get tricky if it gets to freezing as far as the trucks are concerned," he said.