Authorities will continue the search for a teen missing since a Thursday paddling trip on the Conasauga River, but they “are dumbfounded” as to where he might be.

Search teams have used hundreds of people, helicopters, boats, infrared radar, underwater sonar, search dogs and more in looking for Brett Thomason.

Whitfield County Sheriff Scott Chitwood said today the searches will continue, but they don’t know what happened to the 19-year-old who was last seen by two friends at 8:30 p.m. Thursday. They reported Mr. Thomason told them he was going to continue paddling down river in an aluminum, flat-bottom boat.

The boat was found, as were wet clothes the missing man had changed from, and the boat’s oars — all about a mile downstream pulled up on the side of the river.

Sheriff Chitwood said investigators have given a lie detector test to one of the 16-year-old companions of the missing man, but he would not reveal the findings.

He did say they may test the other companion, too, as the investigation continues.