The St. Louis County Department of Health issued an advisory Monday evening urging anyone who recently ignored social distancing guidelines while they visited the Ozarks to self-quarantine for 14 days or until they test negative for coronavirus. On Tuesday, the Kansas Department of Health and Environment also recommended a two-week self-quarantine for those travelers.
The order is a result of reports of huge crowds partying in pools and other locations in the area during the long weekend. Many of the partygoers did not wear masks and were seen close to each other in photos and videos that went viral.
St. Louis County Executive Sam Page said he is concerned these revelers could pose a danger when they return to their homes and workplaces.
“This reckless behavior endangers countless people and risks setting us back substantially from the progress we have made in slowing the spread of COVID-19,” he said in a statement.
Gov. Mike Parson also voiced criticism of the crowds during his daily coronavirus briefing on Tuesday.
"Unfortunately there were some poor decisions that were made and the social distancing was not followed, as we all know," Parson said. "I think it's important when social distancing is not followed. This is potentially dangerous for everyone, especially our most at risk individuals."
The governor added that it was a small sample of the residents of Missouri, and that "there were many other Missourians across the state who did make safe and responsible choices over the holiday weekend."
Parson said it is up to local officials and health departments to enforce guidelines in the state.
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Missouri has 12,291 confirmed coronavirus cases as of Tuesday evening, which represents a 1.3% increase over the last 24 hours and an 8.3% rise over the last week, according to data from the Missouri Department of Health and Senior Services. St. Louis County has the highest number of cases in the state -- 4,583 -- and in the last two weeks saw 635 new cases, health department data showed.
Page instructed St. Louis County employers to screen their employees for health risks and ask them about their travel history.
Kansas has 9,218 total coronavirus cases as of Tuesday and 188 deaths, according to the state's health department. The state has seen a relative decline in new daily cases going from 237 on May 12 to 44 on May 24, according to health department data.
ABC News' Meredith Deliso and Terrance Smith contributed to this report.