A FedEx envelope addressed to Gayle McCaffrey sat jammed into a doorstep crack outside her West Ashley home Monday.

It had been delivered to the missing mother’s Limestone Boulevard house in October. But even as 70 people and dogs fanned out into the woods just to the north and retraced the steps that searchers had treaded before, there was no sign of its recipient.

McCaffrey was 36 on March 18 when her husband, Bob McCaffrey, told deputies he last saw her. He has been dubbed a suspect in what authorities have said is her presumed death.

The Charleston County Sheriff’s Office has been quick to say that the case remains active, that detectives continue to chase down leads.

They have searched portions of West Ashley and Upstate areas near Easley, where Bob McCaffrey traveled on the day she went missing. In one case, a family member’s dream sent authorities on a fruitless search in Newberry County, which has no known connection with the case.

But despite periodic meetings to discuss new angles in the stagnating case, investigators still have no solid information about what happened to Gayle McCaffrey.

“Last time, someone said it’s a cold case,” sheriff’s Maj. Jim Brady said. “But we haven’t put it in a box and put it off to the side. We’re actually working on it.”

Most of Monday’s search was focused on a dumping site for concrete and other construction refuse more than two miles north of the McCaffrey home.

The effort involved seven agencies, including volunteers from The Citadel, where McCaffrey worked. It was not prompted by any new information or hunches; sheriff’s officials already have said that the area was the source of cellphone activity on the night of the disappearance.

The measure simply was designed to revisit the previously searched ground in hopes of stumbling over something that was missed.

A factor in the renewed activity was the weather. Leaves have fallen. Standing water in the forests has dried. Swamps have receded during the winter months, which has a tendency to reveal clues.

In January 2012, for example, a man gathering recyclable cans in the woods near St. Stephen stumbled across the remains of Joe Samuel Swinton, who had been reported missing two years earlier. At the time of his disappearance, which was not suspicious, authorities searched the same area, but they uncovered nothing because much of the land was covered in 7 feet of floodwater.

For members of McCaffrey’s family, finding her remains near her home is not a morbid thought. Helen Banach of Summerville, one of her sisters, said such a discovery would bring peace.

Banach chipped in Monday by serving lunch to the volunteers, rescuers and law enforcers. The First Baptist Church of Charleston, where McCaffrey is a member, cooked batches of chili to keep the crews warm.

“Whenever we get a bunch of people together, it’s that much more of a possibility that we’ll find something,” she said. “It’s another chance to bring her home.”

Bob McCaffrey, 41, has not fielded questions about the disappearance since his first debriefing last spring.

Brady said the Sheriff’s Office has been in contact with the suspect’s attorney, Chris Lizzi, in an attempt to prompt more questioning.

Lizzi has said that his client thinks his wife is still alive and that investigators need to consider other possibilities. The attorney could not be reached for comment Monday.

But Brady said investigations never developed any information to support an alternative explanation to homicide.

“Nothing from the investigation to this point has taken us in any other direction than Robert McCaffrey,” he said.