Police continued to search by land, air and sea for a missing Standish woman Wednesday before rising tides threatened to push the search into a fifth day.

Patricia Hildreth, 56, remained missing as of 3:30 p.m., when Scarborough police and the Maine Marine Patrol halted their search of the Scarborough Marsh, according to Cumberland County Lt. Paul Thorpe.

“The tide is coming in and they’ve pretty much exhausted all areas over there,” Thorpe said. “They’ve gone over it with a fine-tooth comb. Unfortunately, they’ve come up short.”

Several departments have shared equipment and manpower to aid the search for Hildreth since Scarborough police found her car abandoned near a boat dock on Winnows Neck Road on Sunday morning.

Police have used a helicopter and multiple drones to search for Hildreth, while officers on boats have navigated the marsh below, Thorpe said. K9 units also assisted in Wednesday’s search, which began at 7 a.m.

While Scarborough police and the Maine Marine Patrol have coordinated the search effort, the Cumberland County Sheriff’s Office has continued to investigate Hildreth’s disappearance. Police do not currently have reason to believe that she was kidnapped, Thorpe said.

Family members, who told deputies Sunday that it was out of character for Hildreth to disappear, are cooperating with law enforcement but remain worried and upset, according to Thorpe.

Scarborough police and Maine Marine Patrol leaders are planning to meet to discuss plans for a continued search.