In what could be the sixth death on Maine waters this week, game wardens are searching for an Oregon man in Swan Lake after he likely drowned, officials said.

Christopher N. Friedrich, 41, of Springfield, Oregon, was reported missing by his girlfriend Tuesday afternoon, Maine Department of Inland Fisheries and Wildlife spokesperson Mark Latti said.

Game wardens located a camp owner who saw a kayak floating upside down in the lake — as well as personal belongings — on Sunday, and they traced the kayak back to Friedrich. His vehicle was located at the Swanville Boat Launch, Latti said.

The possible drowning follows the death of a South Portland man who fell into the Saco River on Sunday and the recovery of the bodies of two young men who drowned on Messalonskee Lake in Belgrade the following day.

On Tuesday morning, Maine Marine Patrol recovered the body of a fisherman in the waters off Waldoboro, though a spokesperson was unable to say if the death was a drowning since an autopsy is still pending.

Additionally, a 13-year-old girl who was hospitalized after being rescued from the Androscoggin River in Greene on Monday died the next day, the Androscoggin County Sheriff’s Office announced Wednesday.

The Warden Service Dive Team is using sidescan sonar in an area about a half-mile north of the boat launch in the search for Friedrich.