MISSOULA, Mont. -

Officials are scaling back their search for Anthony Bachman, a Missoula man who drowned in Middle Thompson Lake over the weekend.

Search efforts underway since Saturday evening have turned up empty.

Bachman, 62, is said to have been drinking before he fell off a pontoon boat and drowned in the lake southeast of Libby, in northwest Montana. The incident happened around 6 p.m. Saturday. Bachman was not wearing a life jacket.

Lincoln County Sheriff Roby Bowe released an update that as search efforts are scaled back, they will continue to use alternate resources to try to locate Bachman's body.

Officials from Flathead County and Fish, Wildlife and Parks had aided in the search, along with divers using sonar and underwater cameras.

The lake is deep and murky, with very rocky terrain, which has been challenging for searchers.