While people across Minneapolis would normally rejoice on the first warm day of spring, these days, scenes of outdoor recreation carry with them a sense of dread.

Lines of people stroll across the Stone Arch Bridge. Joggers, bicyclists and families with dogs shimmy for space on the paths along Bde Maka Ska. Groups of teens play soccer and basketball in parks across the city.

On Monday alone, the Minneapolis Park and Recreation Board received more than 100 calls to 911 about large groups at parks, Superintendent Al Bangoura said. Gov. Tim Walz pointed out the crowds around city lakes in his daily briefing Tuesday.

Alarmed by the numbers gathering at the city’s most popular lakes and trails as the coronavirus pandemic continues to spread, Bangoura and other parks leaders doubled down on their call for people to spread out and visit smaller neighborhood parks instead. They say that doing so could head off more drastic action, such as closing parks altogether.

“Even though we’re encouraging social distancing … people are still flocking in numbers to some of our most premier locations,” Bangoura said. “We have to understand right now that there’s this concern about people being in spaces as close as they are.”

In an attempt to make it easier for people to practice social distancing, the Park Board closed down parkways along the Mississippi River, Lake Harriet and Lake Nokomis. It has also staked signs with a key message in four different languages: “Stay Safe. Stay Healthy. Stay 6 Feet Apart.”

The board is also considering closing basketball courts and soccer fields, President Jono Cowgill said, something already in effect in other major cities.

It could take even greater measures in the coming weeks and months following the initial surge of the coronavirus, Bangoura and parks commissioners said.

Pools and beaches could close for the summer, and the popular July 4th fireworks along the riverfront could be canceled.

“We’re looking out through the summer and saying the normal things that we’ve done … those are all now absolutely on hold,” Bangoura said. “They’re not happening at this point.”

Cowgill put it bluntly: “There are not going to be large gatherings.”

The scenes could be reminiscent of 1946, when a polio outbreak left the city’s parks and beaches deserted, according to parks historian David C. Smith. The Minnesota State Fair was canceled that year for the same reason.

Forgoing the season’s biggest events would leave a massive hole in the Park Board’s finances, Bangoura said. Commissioners are expected to get a more detailed prognosis during their Wednesday night meeting.

Despite their concerns, the parks leaders said that for the most part, people visiting the lakes are doing their best to keep apart within the space they have.

Commissioner Meg Forney, who lives near the western edge of Bde Maka Ska, said it’s common for people to rush to the lakes once the weather warms.

“The first spring day, everybody is out there in their shorts with pasty white legs,” she said. “We’ve been cabin-bound or housebound. … We just flock to, of course, the lakes.”

Using street chalk, she drew the appropriate distance for people to stand from each other on the trails near her home. Based on what she sees, people do try to avoid each other on the trails.

“That’s not a microaggression. It’s true courtesy,” she said.

Forney said she hoped closing down the parkways didn’t have the reverse effect of attracting more people to already congested parks.

“It’s not really what the intent, the purpose of it is,” she said. “It really is about making sure that we’re all safe.”

In park systems across the country, and in places where the pandemic has reached a more critical stage, harsher measures are being taken. Washington, D.C., on Tuesday closed all its basketball courts, fields, dog parks and other outdoor spaces. Chicago’s mayor closed popular parks and lakefront trails and banned contact sports. Beaches and trails in Los Angeles are also closed.

About 74% of parks agencies had closed playgrounds and 69% closed outdoor fields and courts as of last week, according to a member survey by the National Recreation and Park Association.

The association is encouraging governments to keep parks and other green spaces open as long as people can practice social distancing. Studies show that parks and other open spaces help reduce stress and provide physical and mental health benefits, according to Allison Colman, the association’s director of health.

Cowgill said he hoped people in Minneapolis heed the Park Board’s advice to visit less-crowded parks so the entire system could remain open.

“We don’t want to get to a point … where we’re putting up signs saying ‘Don’t come to this park’ or shutting down spaces,” he said. “We don’t want to be in that situation.”