On a snowy night in Minneapolis, on the upper concourse of a billion-dollar football stadium, couples on Rollerblades glided by, hand in hand.

This is the people's stadium, built with the people's tax dollars. So on select winter weeknights — when no sports teams or concerts or monster truck rallies need the space —the people playing in U.S. Bank Stadium are wearing in-line skates and running shoes.

"There's 8 inches of snow outside and we're here and it's beautiful and it's only the first night," said chief skate guard Lee Engele, smiling at the hardy souls who turned out for Winter Warm-Up at the stadium this week.

"There could be 10 feet of snow, I'd still be here," a skater called out to her in passing. The skaters zoomed around one concourse. One level up, a handful of joggers ran laps.

Minnesotans have run and skated circles around their pro football stadiums for decades. The old Hubert H. Humphrey Metrodome — on the nights it was known as the Rollerdome — offered skate rentals and opened the concession stands so families could make an evening of it.

Engele used to work the Rollerdome, sometimes skating eight to 12 hours at a stretch.

"It was a social affair. People came, families came, couples came," she said. "They'd come, they'd skate, they'd get some snacks, maybe sit awhile. They wanted every minute, every penny's worth of their time. They skated the whole 5-to-9 time."

When the shiny new stadium opened in 2016, the tradition continued — pared back and priced up.

Winter Warm-Up tickets are $15 through Ticketmaster this year. Last year, the price was $12. In 2019, it was $8 for adults and $5 for children. When the stadium opened in 2016, runners paid $3 a night and skaters paid $6.50.

Stadium staff attribute the rising cost of fun to the rising cost of operations — lights, music, signage, staff at the door to check tickets and screen for weapons, and skate guards like Engele who can swoop in with ice packs and moral support if someone takes a tumble.

"We look forward to welcoming the community to U.S. Bank Stadium each year for Winter Warm-Up," John Drum, general manager for ASM Global at U.S. Bank Stadium, said in a statement. "Skating and running inside the home of the Vikings during the winter months is a beloved, long-standing Minnesota tradition."

If any other pro football stadium doubles as a roller rink, staff at U.S. Bank aren't aware of it. Although the Green Bay Packers do offer a sledding hill.

Fifteen bucks might be one of the cheapest tickets into the people's stadium these days. But it's a lot for a night of jogging, or for a weekly family skate night, or for the pee-wee hockey league coaches who used to take their whole teams skating at the stadium as a treat. If you went each night, $15 a night, times 18 nights, plus the cost of transit or parking would add up to hundreds of dollars.

Minnesotans chipped in $348 million to build the stadium — plus another $150 million from the good people of Minneapolis. Which apparently does not entitle any of us to a free skate night. So far, no one in the Vikings franchise — or any other entity getting rich off the stadium we built for them — has stepped in to offer to offset the rising cost of Winter Warm-Up.

For those who love this uniquely Minnesotan tradition — and can still afford it — it's worth the price.

"I come almost every week," said Mark Lindblom of Plymouth on the first night of the stadium's Winter Warm-Up calendar.

Lindblom switched to in-line skating after running got rough on his joints. Now 70, he trekked to the stadium through Tuesday's winter storm, just as he has for years. Two and a half laps around the concourse equals a mile, which makes it good training for the distances he covers when he competes in the NorthShore In-Line Marathon with his daughter, Jennifer.

"It's something that's cool that you can do with your kids," he said. "My daughter, she calls me and says. 'Dad, are you going roller-blading?'"

For runners — who were hit with the steepest sticker shock — running laps around an airy stadium offered a break from treadmills or icy sidewalks or endless loops around cramped gym tracks.

For skaters, hit by the loss of the Roller Garden and other local rinks, the smooth concrete concourses beckon everyone from families with small children to the elite speed skaters who start making blistering full-speed runs around the stadium late in the evening.

The stadium is opening its doors for 18 Warm-Up nights this season. Tickets are only available online through Ticketmaster.