The melee at Mount Olympus Water and Theme Park was captured on cellphones and video of the mayhem over something so minor was posted on social media.
Lake Delton police anticipate filing charges.
Authorities were sent to Mount Olympus at 4:15 p.m. Sunday. The large water park features both indoor and outdoor pools, roller coasters, go-karts and other amusements. Its faux Roman Colosseum and huge Trojan horse are a fixture on the main drag through the popular tourist destination.
By the time police arrived, the fight was over. Officers talked to witnesses and looked at video shot by bystanders. It's unclear if there were injuries.
The police chief said in the release that he was "disappointed that cooler heads did not prevail" and an argument over a chair escalated into a brawl at a family-oriented business.
Mount Olympus officials are cooperating with police, according to a statement released Monday afternoon by Director of Safety Jason Hammond, who thanked officers for their quick response.
"Mt. Olympus is very disappointed to have had an altercation between several of our guests this past weekend. Guest safety is always our first priority. We are thankful that no one was seriously injured."