Investigators aren't sure why 24-year-old Alex S. Hrabik of Omaha entered the Platte River Friday night.
But they received a missing person's report on Hrabik Sunday and believe they may have recovered his body Monday morning.
Police say Hrabik parked at the public ramp late Friday afternoon where Highway 50 crosses the river.
Witnesses say he walked into the river wearing swimming trunks.
When asked if he needed help, Hrabik who witnesses say appeared to be irrational, refused assistance.
Another witness operating an air boat also asked Hrabik if he needed help and again he said he was fine.
Hrabik has not been seen since.
The body of a young male was found just before 8AM Monday two miles down stream from where Hrabik entered the river.
Channel 6 newsman Roger Hamer was on the scene as deputies from the Sarpy County Sheriff's department worked to retrieve the body from the river.
Investigators have not positively identified the body recovered Monday morning as that of Hrabik.
The swimmer may have underestimated what he was getting in to.
"There's always a current and you never know where that channel moves to," Yost said. "There could be holes. You hit those holes and you go down. You hit a tree or something underneath. You get caught up and you can't get away from that any that's possibly what happened here."
Just across the river, Sheila Swanson is supervising her kids and granddaughter as they swim at a designated area of Louisville State Park.
Sheila has strict rules.
"You do not go where you cannot touch and you don't go past the buoys and they all watch each other and I'm usually right on them," she said.
Sheila and the kids have had several discussions about the dangers of area rivers.
"It's not as safe," she said. "You don't know how deep it is. There's nobody watching you. There's a place to swim and a place not to swim and that's not a place to swim."
An autopsy is scheduled for later this week.
The death is being investigated as an accident.