FBI: Body of Mont. teacher Sherry Arnold may be buried on vacant farmland

(CBS/AP) SIDNEY, Mont. - Authorities investigating the suspected death of Montana teacher Sherry Arnold are requesting help from landowners in Montana and North Dakota.

Law enforcement officials asked property owners in three counties to check vacant farmsteads for signs of disturbed soil or matted grass, saying Arnold's body might be buried at such a site.

Multiple sources last week reported that Arnold had been found dead, but the Huffington Post says Arnold's husband and the mayor of Sidney, Mont. are contradicting those accounts. 

CBS affiliate KRTV reports the FBI said in a press release that based on investigative evidence gathered, it is believed that Arnold may be deceased but that her body has not been recovered.

The FBI said Sunday the body of the 43-year-old high school math teacher might be buried in a "shelter belt," or a line of trees that protects soil from the wind.

Police released the names of two men being held in the case and planned to hold a news conference Monday. Lester Vann Waters and Michael Keith Pell, of Colorado, were in a North Dakota jail, awaiting extradition to Montana, authorities said.

Williams County Sheriff's Deputy Jon Garrison said Walters and Spell face aggravated kidnapping charges in connection with Sherry Arnold's disappearance in Montana. On Friday, authorities received tips that led them to the two men.

Police will not release where or how the men were taken into custody. Police Chief DiFonzo says he does not know if the two were passing through the town of Sidney or working in the nearby oil fields when the crime occurred. Authorities have a truck in custody.

Sherry Arnold disappeared while on an early-morning run nine days ago along a truck route on the edge of the oil boom town of more than 5,000 residents.

In the days after her disappearance, hundreds of residents and law enforcement officials combed the town and surrounding area without success. The only clue that has been publicly released was that one of Arnold's shoes was found along the running route.

Arnold was married and had five children. She had been a school teacher for 18 years.

Complete coverage of the Sherry Arnold case on Crimesider