Authorities are staying tight-lipped about their investigation into a Montana teacher who is missing and presumed dead, as they call on landowners in North Dakota's northwest corner and in far northeast Montana to look for her buried body.

Williston, N.D., Police Chief Jim Lokken said at a news conference Monday that officials are asking "landowners and landowners only" to search for signs of 43-year-old Sherry Arnold. He says they should be on the lookout for soil or grasses that appear disturbed — especially in areas with lines of mature or rotted trees.

The Billings Gazette reports (http://bit.ly/AAQq7e ) authorities said little of the two Colorado men believed to be involved in the Jan. 7 disappearance of the Sidney, Mont., math teacher.

The two — 47-year-old Lester Vann Waters Jr. and 22-year-old Michael Keith Spell — are awaiting extradition to Montana.

Waters was arrested in Williston, and Spell was arrested in Rapid City, S.D.