We darted across the frozen lake wearing wool socks and swimsuits, the icy snow crunching beneath our feet.

Under the pitch-black night sky, steam radiated off our bodies like translucent capes in the below-freezing air after sitting in the 200-degree sauna. A lantern on the ground marked the ominous black hole carved in the ice. One by one, my three friends fearlessly leapt into the frigid water, exhaling in shock before dashing up the wooden ladder back to the Finnish sauna.

Rinse and repeat.

“It’s magical,” I said as we sat breathlessly in the dim light from a single kerosene lamp hanging in the window.

Camp du Nord outside Ely, Minn., is a quiet escape to a winter wonderland on the edge of the wilderness.

The northern Minnesota YMCA facility may be best known for its popular summer camps that draw hundreds of families for a packed schedule of activities, meals and presentations after selling out in a December lottery each year. In a sign of just how popular the family camps are, YMCA of the Greater Twin Cities, which owns Camp du Nord, just bought two lake resorts in nearby Babbitt to open Camp Northern Lights, its eighth overnight camp.

But camps like du Nord are also increasingly catering more to adults, women’s groups and couples in the spring, winter and fall, offering a calmer retreat to a rental cabin that allows you to explore on your own.

“It has just been getting busier and busier,” said Emily Weise, who grew up attending the camp and now runs its fall, winter and spring programs. “It becomes more of a focus every year. It’s like our worst-kept secret. ... It’s just an amazing time to be up there.”

During our weekend at Camp du Nord, we swapped crowds and traffic for the peaceful solitude of the North Woods, slowing down to watch the crackle of the fire over glasses of wine, to snowshoe among towering red pines and, of course, to steam in a sauna.

In the 1930s, three schoolteachers from the Iron Range started the resort on a slice of land on Burntside Lake, giving it the French name for “camp of the North,” in honor of the voyageurs who trekked and canoed through the region during the fur trade. Finnish carpenters, most of whom didn’t know English, built the first log building in 1933 to serve as their bunkhouse while they built the resort’s other structures. Just steps from the lakeshore, that first log cabin was later converted to the sauna.

The YMCA bought the camp in 1960 for $50,000. Since then, the site near the Boundary Waters Canoe Area Wilderness has drawn generations of visitors, expanding along the way by adding cabins — including year-round lodging in three different “villages” along the lake.

In the winter, most of the camp’s 29 cabins are open. The camp offers free use of cross-country skis and snowshoes and has groomed trails and a tubing hill.

Exhilarating plunge

But the main attraction may be the saunas. Besides the traditional wood-fired sauna, the camp has an electric sauna and a barrel sauna, the latter of which it will replace this spring with a combination wood-fired and electric sauna. The saunas have become increasingly popular, so much so that Camp du Nord started an annual “sauna enthusiast weekend” two years ago for visitors to learn more about the Finnish tradition.

“I didn’t realize there was this subculture around it,” Weise said. “Word is getting out more that du Nord has this awesome sauna. This is a big reason why people come. It’s just a really great way to experience winter.”

After snowshoeing through the deep snow to Old Baldy, a rocky high point on the trails next to the camp, my friends and I hustled to the traditional sauna for our reserved time slot. Not a star was visible in the cloudy night sky as kerosene lanterns cast dramatic shadows and illuminated the thermometer, the arrow surpassing 200 degrees.

“Ready?” I asked after several minutes inside, sweat dripping off our faces.

We ran into the crisp night, yelping as we crossed the ice and jumped into the lake in the exhilarating late-night polar plunge — or avantouinti, the Finnish word for ice-hole swimming.

“Ahh, cold, cold, cold!” we screamed as we jumped in, the water coming up to our chests. While in the summer, you can slide timidly into a lake, the ice hole in the winter forces immediate immersion into the chilly water.

After an hour at the sauna, we dunked freshly cut slices of grapefruit into glasses of Champagne for a refreshing drink followed by a cozy chat around the roaring fireplace in our cabin.

The cabin at Pine Pointe Village, which was built in 2000 and is open year-round, had a full kitchen, North Woods-themed living room furniture and two bedrooms, one with a twin bed and bunk bed and another with a queen bed. Limited cell service and no TV or Wi-Fi encourage unplugging, so we spent evenings cooking and playing games.

The next day, awash in the monochrome gray-white palette of winter, we trudged across nearby Hegman Lake until our snowshoes were weighed down by thick snow.

We returned to Camp du Nord. A couple of snowmobiles zoomed past the scattered fish houses on the lake, but we didn’t see anyone else in the silent, still winter afternoon. It was time for another sauna.

Getting there

Camp du Nord is located a half-hour from Ely, which is four hours north of the Twin Cities. To book a cabin, go to ymcamn.org/camps/camp_du_nord. In the fall, winter and spring, prices range from $105-$645 a night for a cabin housing two to 16 people. You have to bring your own linens or sleeping bags, and clean the cabin before you check out.

Other attractions

Snowshoe or ski nearly 2 miles on Hegman Lake to view ancient pictographs created by American Indians on a granite cliff (free, fill out a day-use permit for the Boundary Waters Canoe Area Wilderness; more details at bit.ly/2HxCQyA).

Go dog sledding with Wintergreen Dogsled Lodge (trips start at $125 for children, $150 for teens and $175 for adults for a half-day and range from $200 to $300 for a full-day trip; dogsledding.com).

Grab dinner and drinks at Insula, a restaurant on Ely’s main street (145 E. Sheridan St., insularestaurant.com). And if you can’t get enough of saunas, check out the Ely Steam Sauna ($7, open 4-8 p.m. on Wednesdays and Saturdays; 1-218-365-2984).

If you’re really lucky, maybe you’ll even catch a free show of the elusive Northern Lights dancing in the sky.