IDAHO FALLS, Idaho -

Bureau of Land Management and Idaho National Laboratory firefighters "knocked down" a range fire about 20 miles west of Idaho Falls near U.S. Highway 20 on Monday. It was initially estimated at 150 acres.

The fire started around 2:30 p.m. and was quickly attacked by INL firefighters. BLM crews helped bring the fire under control.

According to BLM spokesperson Sarah Wheeler, the fire is believed to have been human-caused. An investigation is under way.

As of Monday afternoon, the BLM was also watching a fire near American Falls. The Aberdeen Fire Department has been sent to the scene. The cause and size of that fire have not been determined.