CANAAN – A cadre of more than 40 volunteers, 15 game wardens, state troopers, six search-and-rescue horses and a pack of cadaver dogs on Saturday morning began searching several locations in Canaan and Palmyra for a missing Canaan woman.

They worked in a grid, sometimes shoulder to shoulder, sometimes taking rarely used trails, while searching for Shirley Moon Atwood, 35, who has been missing from her Canaan home since late July.

The daylong search revealed nothing new, police said.

Part of the search centered on a deeply wooded area off Route 23 where police found the body of Cheryl Murdoch, 37, more than a month ago.

It was while police were investigating Murdoch’s disappearance and homicide that they discovered Atwood also was missing and probably had been missing for several weeks before Murdoch’s death. The two women had lived in the same home in Canaan.

So had Shannon Atwood, 37, Shirley’s estranged husband. Two days after finding Murdoch’s body, state police detectives went to the home to question Shannon Atwood about Murdoch’s death. Atwood reportedly barricaded himself and held police at bay with a bow and arrow.

Atwood is being held in Somerset County Jail on charges of terrorizing, reckless conduct, and reckless conduct with a dangerous weapon.

Maine State Police Lt. Gary Wright said Saturday’s search was important because the leaves are going to fall soon and obscure either a body or important evidence.

“Using what we already know, it is common sense to go back,” Wright said.

New information about Atwood’s activities in July prompted searchers to also head to two locations in Palmyra.

“We got some new information about some possible sightings of suspicious activities,” Lt. Pat Dorian of the Maine Warden Service said.

Dorian explained that by using a grid search, the large area could be covered more thoroughly.

No one has been charged in Murdoch’s death, and police are tight-lipped about how she died, whether she died at the mobile home or somewhere else, and whether they believe Shirley Atwood has also met foul play.

They also have not revealed the relationship between the three people.