HUNTINGTON — Since sometime before Wednesday, when Robert Sherman’s rental vehicle was found stuck in snow on Norwich Lake Road, the 79-year-old Chesterfield resident has been missing, not returning to his home, answering phone calls or getting in touch with family or friends.

The last time anyone saw or spoke to Sherman was two days earlier, when a surveillance camera in Westfield captured his image. He last made a phone call Feb. 7 at 12:04 p.m.

Now, following three days of extensive searching in and around Norwich Lake by local and state police, both on the ground and in the air, there are still no signs of Sherman, prompting his family and Massachusetts State Police and Huntington Police to put out appeals to locate the man who his stepdaughter Merle O’Neal said could get easily confused.

“The craziest thing is that there’s no sign of him,” O’Neal said Sunday from her home in Los Angeles.

With the pond frozen over and people fishing on its surface, O’Neal said she has been told it is unlikely that Sherman fell in, and the scouring of the woods turned up no sign of him. It has led her to wonder if he was able to walk out to Route 66 and hitchhike away, even though by nature he’s very cautious.

“We are absolutely flabbergasted as to how he’s evading the public. It’s been impossible to fathom,” O’Neal said.

She has posted photographs to Facebook and Instagram in the hope that someone might have seen him.

“Although it’s nearly impossible not to assume the worst, I cannot give up because I know he would never stop looking for me,” O’Neal wrote in a Facebook post she is encouraging people to share.

For O’Neal, the fact that Sherman has not returned home or been found safe has caused her intense sadness for the man she has known as Bob, who brought her family from Cape Cod to the Pioneer Valley in the early 2000s.

“I’m very hopeful in a weird way,” O’Neal said.

As Sherman continued to live on his own, he could also be easily confused, exhibiting some dementia, O’Neal said. In fact, he was using the rental vehicle following an incident in Westfield that ended with his own vehicle being impounded. He got the loaner after initially approaching the Hilltown Community Development Corp.’s free transportation service.

O’Neal and her brother, Dan Lake, began wellness checks when Sherman didn’t again make contact with Hilltown CDC after going to Westfield, and also missed a doctor’s appointment on Wednesday. Their mother found his home vacant, and their phone calls to him went unanswered. Lake filed a missing person’s case just hours before the rental vehicle was found stuck in snow on an unplowed road near Norwich Lake.

Lake, who last talked to Sherman on Feb. 5, said not having closure is the hardest part. “The not knowing is terrible,” Lake said

O’Neal said she considers Sherman “fiercely independent,” but even so she said these circumstances can show other families with senior citizens about the need for resources to support their loved ones.

She adds that her family is grateful for the help it is receiving. “There’s been unrelenting kindness from people I know and who I don’t know,” O’Neal said.

Lake drove from his home in Falmouth to get a better sense of the situation confronting the search teams.

“We appreciate how much people are willing to help,” Lake said, adding that he’s not surprised the residents of the Hilltowns would step up. “It’s good to know people care.”

O’Neal and Lake are encouraging people to call State Police at 413-587-5700 if they have any tips or leads.

Scott Merzbach can be reached at [email protected].