The Los Angeles County Sheriff's Department says the body of 64-year-old Jack Thirasack of Baldwin Park was found Wednesday morning at Pyramid Lake.
Investigators believe he and 52-year-old Rick Tanovan of West Covina were on a boat that sank on Sunday.
A man on a personal watercraft alerted authorities to the bow of a boat sticking out of the lake. Tanovan's body was found nearby.
Thirasack's fishing license also was found, prompting the search for his body. It was found about 20 feet from shore.
Authorities believe both men drowned.
Investigators say there's no sign of foul play but the cause of the sinking is under investigation.