If your teen wants to visit Six Flags St. Louis, they now need a grown-up with them at the gate.

The Eureka theme park reactivated its chaperone policy on May 2 after a large fight on opening day forced the park to close early. Under the rule, anyone 16 or younger must be accompanied by an adult at least 21 years old carrying a valid government-issued ID.

The opening-day incident on April 26 involved as many as 100 people, most of them juveniles, according to news reports. Eureka Police Chief Michael Werges said officers responded quickly, detained about half a dozen juveniles, and dispersed the crowd. No injuries were reported and no damage was done to the park, Werges said.

Here's what families need to know about the chaperone policy:

• The adult must show government-issued ID at the ticket entry point.
• One chaperone can supervise no more than six guests aged 16 or younger.
• The chaperone must enter with their group and stay in the park, reachable by phone and in person, for the entire visit.
• Guests 16 and under found without a chaperone could be ejected.

The park also announced that full or partial face coverings, including hoods with front zippers, ski masks, and neck gaiters, are no longer permitted inside.

Six Flags St. Louis opened for 2026 under new ownership by Enchanted Parks, one of seven properties the company acquired. The park has not specified whether the chaperone policy will apply to all operating days or only designated weekends.