Gayle McCaffrey’s 5-year-old son recently stared out a window, his mind consumed with thought.

“How in the world did my mom get this lost?” he said.

It was a heartbreaking moment recalled by loved ones of the 36-year-old mother who disappeared one evening in mid-March.

But this morning, 230 miles from her West Ashley house, detectives and volunteers plan to scour an Upstate property where her husband, the suspect in her presumed death, might have traveled that night.

Bob McCaffrey never arrived at the family’s house on a 200-acre parcel near Easley, but the Charleston County Sheriff’s Office has long targeted it for a search. Family members consider the effort one of their last hopes for bringing the mother of two home.

“It’s only going to get worse if they do find her on the family’s own property,” said Helen Banach of Summerville, Gayle McCaffrey’s sister. “But it would be a step in the right direction, to bring this all to an end.”

The effort is not based on new information in what officials consider a homicide investigation, sheriff’s Maj. Jim Brady said.

The heavily wooded land off Freeman Bridge Road is just outside Travelers Rest, where Bob McCaffrey was ticketed for speeding early on March 18, the day he reported his wife missing.

Deputies will combine forces with the North Carolina-based CUE Center for Missing Persons, which in August offered its volunteers, equipment and search animals. A family member has already conducted cursory looks on the land but has found nothing.

Past efforts to find clues and perhaps McCaffrey’s body have included fruitless sweeps near the couple’s home on Limestone Boulevard. Those were based on cellphone signals, though today’s effort is not, Brady said.

“It’s in the proximity of the locations he had access to,” Brady said. “As we have said all along, there are areas we determined that need to be looked at, and it’s one of them.”

The couple, whose marriage had been tumultuous, had a disagreement during a St. Patrick’s Day dinner. Bob McCaffrey then took a trip upstate to visit a love interest, but the woman turned him down, according to authorities.

The 40-year-old contractor reported that he came home and found his wife gone and their children home alone. Left behind were her personal belongings and a note saying she had gone to live with another man.

Sheriff’s investigators have long suspected McCaffrey in his wife’s presumed death, but they have not gathered any solid evidence in connection with a crime.

McCaffrey’s attorney, Chris Lizzi, said Friday that his client has been trying to return to a normal life. Every two weeks, he visits his son and daughter, who are living with an aunt in Mount Pleasant.

Lizzi hasn’t spoken with his client since the last public development in the case this summer, when billboards countywide asked people to phone in tips. That effort also yielded no leads.

“He still has the same position: He wishes his wife would show up,” Lizzi said. “Whatever effort they are doing to find her, he just hopes that they won’t keep pointing the finger at him.”

McCaffrey planned to visit his children today as searchers trudge through forests and creeks on the Upstate property.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede