Authorities and local residents in a rural Montana oil town fanned out Tuesday in search of a popular high school math teacher who disappeared while jogging over the weekend.
The only publicized clue into Sherry Arnold's Saturday disappearance was a single running shoe, found by a ditch along her running route in her hometown of Sidney.
Authorities were searching hard Tuesday to find some sign of Arnold before snow, rain and freezing cold moved in later in the day.
The FBI and local law enforcement are investigating the possibility that Arnold was abducted from the town along the North Dakota border, which has been changing rapidly in recent years due to an oil boom.
After three days of searching by hundreds of residents, police, firefighters and others, the plan was to re-canvass areas around town that already had been searched at least once, officials said.
If nothing new in the case emerges, authorities said they would consider scaling back the search.
“It’s been tough having known the family for awhile, something like this just doesn’t happen here,” said John Seitz, who is leading one of four groups searching for clues.
Search crews had broadened their grid in Richland County walking fields, searching trailer parks, ditches and canals on Monday. They found other items of clothing, but none -- apart from the shoe -- have been identified as belonging to Arnold.
No solid evidence has emerged to indicate that she was kidnapped, authorities said.
"It's just been grueling," said Arnold's father, Ron Whited, who runs a ranch outside of Sidney. "When you can't find someone and you do find a shoe and you know that's where she was running, something obviously wasn't right. I can tell you I would never believe I would be looking for my daughter."
Sherry and her husband, Gary Arnold, had five children from previous marriages, including two still living at home and attending Sidney High School, Whited said. Colleagues described her as a devoted teacher.
Her disappearance comes amid a lot of change in the town of more than 6,000. A boom in the nearby Bakken oil fields of eastern Montana and western North Dakota has brought in newcomers, up more than 1,000 from several years ago.
"It’s not the little town Montana anymore. Stuff like that isn't supposed to happen here,” Seitz said.