Land owners in Montana and North Dakota are searching their properties, looking for the body of missing Montana teacher Sherry Arnold.
The farmers and ranchers in these remote areas were asked by the FBI to check for disturbed soil or grass near vacant farms.
Investigators are saying that Arnold could be buried in a "shelter belt," rows of trees planted alongside farmland to protect the soil from wind.
"Property owners who discover something unusual are asked not to disturb the site and immediately contact the Williams County Law Enforcement Center," the FBI said in a statement.
Arnold, 43, a married mother of two and stepmother of three, disappeared on Jan. 7 around 6:30 a.m. while jogging near her home in Sidney, Mont. A single running shoe was the only trace left behind.
Two Colorado men are being held in connection to Arnold's disappearance. The men are Lester Vann Waters Jr., 47, and Michael Keith Spell, 22.
The two men are in the Williams County Correctional Center in Williston, N.D., as they await extradition to Montana.
Waters and Spell have been charged with aggravated kidnapping. The case is now a federal case because investigators believe Arnold was kidnapped from her hometown of Sidney, Mont., and taken across state lines.
The two men were taken into custody on Friday, but officials have released very few details about what led them to the men or the conclusion that Arnold is dead.
Sidney Mayor Bret Smelser said the tight-knit town is in shock.
"We're grieving," Smelser said. "We've got to get through that process. We've got to get through the closure."
Arnold's family is hoping to find Arnold so they can move closer to gaining some closure.
"We pray that we can find Sherry. We want it to be done," the Arnold family told "Good Morning America."
Sidney, a small town of roughly 5,000 people, has experienced an influx of out-of-town oil workers following the Bakken oil boom in North Dakota. Crime rates in the area have also swelled, with a rise in bar fights, domestic violence and drunk driving.