The two people that died after a tornado ripped through a farmhouse Monday night near Reserve, Mont., -- about 50 miles northwest of Williston -- have been identified.

Robert "Robby" Richardson, 10, and Steven D. Smith, 46, died of blunt-force head and chest injuries at the farm 13 miles west of Reserve on Monday night, Sheridan County Coroner David Fulkerson said.

Barbara Smith, 71, was taken from the basement of her home to a hospital in Plentywood and was later transported to the Billings Clinic, where she was listed in serious condition Tuesday evening, hospital spokeswoman Julie Burton said.

The tornado that touched down west of Reserve about 7:15 p.m. Monday was reportedly two to three miles wide with winds estimated at 150 mph, National Weather Service spokesman Brad Mickelson said.

That wind speed put the tornado's rating at EF3 on the Enhanced Fujita Scale, making it only the fourth tornado in Montana's history powerful enough to achieve that rating, Mickelson said. It's the deadliest tornado to hit the state since 1923, he added.

Medicine Lake resident Brandon French said he and five other men watched the tornado from a hillside.

"It was a damn big one. It was a long way away, but you could see it clear as day," French said. "It was like nothing we've ever seen before."