Park spokeswoman Rainey McKenna says the man was sitting on the lake shore at dusk on Aug. 12 when a bat flew out of a nearby tree and landed on him. The man knocked the bat to the ground and was scratched in the process. He used a towel to capture it and alerted park staffers.
Tests confirmed the bat had the rabies virus.
The man was not identified.
Rabies is a viral disease that causes inflammation of the brain. If untreated, it is fatal.
The park says there have been only two other known cases of rabies in Olympic National Park bats. In 1975, a child was bitten by a bat in the Elwha Valley and in 2008 a woman was scratched by a bat in the Ozette Campground.