BOISE COUNTY -- The family of a missing Kuna man says every day that passes without hearing from him increases their fears that he was swallowed by the swollen river alongside Highway 55.

Jerry Coburn, 43, was reported missing after he failed to return from a fishing trip Sunday night. His in-laws, Brandy and Bob Lee, said he had headed north on Highway 55 that morning with plans to fish at Horsethief Reservoir.

The Boise County Sheriff's Office says someone spotted a northbound pickup veer off the highway and into the Payette River at about 9 a.m. Sunday, just north of the Gardena Bridge.

"The time that the vehicle left the roadway and entered the water coincides with the time he would have been in that area," Bob Lee said.

"A visual description of the truck is very similar to what he was driving," Brandy Lee said.

The Lees said they were told the man inside the pickup made it out of the vehicle and was clinging to the hood, but was washed downstream before rescuers could reach him.

MORE: Search for pickup in Payette River turns up empty

Chief Deputy Steve Dorau said Wednesday the witness described the pickup in the water as blue or gray, but couldn't identify the make or model. Coburn was driving a blue Ford F-250 crew cab pickup, his family says.

Emergency responders searched the water for the pickup and its occupant, but came up empty.

Dorau said the sheriff's office won't be able to say if the man was Coburn until they recover the truck or a body.

"We can not confirm that it was him by any means," he said. "We have no license number, no nothing."

Since Monday, Jerry's family, including his stepbrother Michael Taggart have searched the river; scouring the banks of the Payette looking for any type of answer.

"We've been here for days looking for him. Hiking up and down both sides of this all the way down to Horseshoe Bend and then all the way down through Old Emmett Road," Taggart said. "We've had folks that brought drones out yesterday looking for any sort of sign. We haven't seen anything, no sign of the truck, no sign of him or any of his belongings."

Brandy Lee tells KTVB when Coburn didn't come home Sunday night, his wife and 18-year-old son drove up to Horsethief Reservoir to look for him.

"The next morning at 6, 6:30 she texted me that they just got back. They drove all the way to Horsethief, drove all the way around those campsites," Brandy Lee said.

Dorau said Coburn's family reported him missing, and have been in touch with the sheriff's office.

The official search is currently on hold for safety reasons until the water goes down, he said.

"We're just kind of at a standstill," Dorau said. "That river is really running wild right now."

However, the family says they will not stop until they find him.

"The best man you'll ever know, just so loyal, so loving. He loved everyone around him. He would do anything, anything and that's what we're doing now," Brandy Lee said.

So since Monday, the family has continued to search for any type of closure.

"He wouldn't leave that river without finding us if it was one of us in there, and I'm not," Brandy Lee said.

"Whether he's with us anymore or not, we need to bring him home and until we do, nothing else can be done. We can't leave him out here. He wouldn't leave us, can't leave him," Taggart said.

The sheriff's office has asked the public to keep an eye out while rafting or fishing on the Payette River. Anyone with information is urged to contact Boise County dispatch at 208-392-4411.