Finnerty, 30, who led the Lakers to NCAA Division II championships in 2003, '05 and '06, was reported missing late Sunday after he went fishing at a campground near Baldwin, Mich., the news website Mlive.com reported Tuesday.
His boat and fishing gear were discovered Sunday, WWTV-TV, Cadillac, Mich., reported.
Finnerty's body was found in the woods near the campground, Lake County Sheriff Robert Hilts said at a news conference, USA Today reported. He was wearing fishing waders and a camouflage jacket.
"There was nothing obvious to us, to the view, of anything that would have caused his death," Hilts said.
Police said Finnerty called his wife Sunday to tell her he was in danger.
"He was such a huge force here, during a great period," Grand Valley State football Coach Matt Mitchell said.