The discovery was made late Saturday night inside a concession stand at a former little league baseball park on Fallon Drive.
Benton County Coroner John Hansens says someone had noticed a strange smell and called the police.
Hansens says the body is that of a 20 to 30-year old man and could have been inside the building for several days.
The coroner has not been able to make an identification yet and may have to resort to dental records.
Hansens did say he knows the cause of death, but is not releasing that until he notifies the next of kin.
A shotgun was found near the body, but the coroner says he does not believe there was any foul play.