The other day as a pair of Canada geese arrowed overhead, Jim Smith tossed a log on a fire, above which maple sap boiled in a stainless-steel pan.

The geese might have just arrived from points south. Or perhaps they were locals that had passed the winter in Minnesota. Either way, flapping their wings and honking, and flying low, as if curious, the birds and their arrival seemed synchronous with Smith and his fire-tending.

During these warming days and still-cool nights, similar sap-burning fires will crackle throughout Minnesota, Wisconsin and many other states.

Silver maples will discharge the season’s first sap, followed by sugar maples. When both flow freely, men, women, boys and girls will collect bag after bag of the sweetened water and carry it to fires that in many cases are kept ablaze all day and all night.

“I got into this kind of by accident,’’ Smith said. “My neighbor was having a garage sale and I went over there to see what they had. One thing led to another and … here I am.’’

Where Smith is, is in his backyard, not far north of Stillwater. Dave Swager was there the other day, too, as was Vince Anderson. Each is a member of a five-family syrup-making operation that to the casual observer might resemble a moonshiner’s hooch factory.

“We didn’t know Jim when he came to the garage sale, which was at the home of Pam and Eric Lindberg, who are in our syrup-making group,’’ Swager said. “But when we found out Jim owned the house we had been watching that had a yard full of sugar maples, we were glad to meet him.’’

Syrup makers often keep one eye peeled for maple trees whose full potential is not being realized. Meaning they are not being tapped. Owning such trees is best. Next best is knowing the trees’ owner, or knowing someone who knows someone who knows the owner.

Last year, Smith, et al, tapped 500 trees, a big number for what is essentially a hobby operation.

“Some people don’t even know they have maples, or if they do, they don’t tap them,’’ Swager said. “If we get permission to tap them, we’ll trade the owner finished syrup in return.’’

Between winter and what in these parts passes for spring — a time when lake ice is too weak for fishing and turkey hunting hasn’t yet begun — syruping season unfolds.

Rising temperatures and flying geese are the hallmarks of this in-between time. But wood ducks also are returning just now, as are mallards, sandhill cranes and great blue herons, as well as bluebirds and eastern phoebes, among other spring songbird pioneers.

Immersing oneself in this environment can free the mind. But labor is required, with 35 to 40 gallons of sap needed to produce just 1 gallon of syrup. Cords of firewood also must be gathered and split.

But there’s a payoff: 100 percent, all natural, maple syrup — not high fructose corn syrup or another modern-day sweetening impostor.

“I put syrup on ice cream, cornbread and apple pie,’’ Vince Anderson said. “It’s more than just for breakfast, on pancakes and waffles.’’

A senior at Iowa State University majoring in chemical engineering, Anderson was in sixth grade when his dad, Steve, along with Swager and the Lindbergs got tangled up in syruping.

“The ‘cooker’ we use now is the smallest commercial-size cooker that is made,’’ Swager said. “We can boil 35 gallons of sap an hour. But when we started, we just stacked some cement blocks and built a fire, with a pan on top for the sap that previously had been a salad bar liner.’’

• • •

In addition to Swager and his wife, Denise, Smith and his son, Noah, Steve and Vince Anderson and the Lindbergs, Larry O’Connor of Houlton, Wis., is a member of the syruping group that is headquartered in Smith’s backyard.

Their cooker, which they bought used a few years ago for $4,000, sits beneath a 20x22 open-sided shelter.

“This actually is the first year we’ve cooked here,’’ Swager said. “We got the shelter built last fall and moved the cooker here from Pam and Eric’s home.’’

This spring the group has 435 taps spread among five locations in the greater Stillwater area. A 220-gallon plastic farm-style tank that sits in the back of a pickup truck is used for collecting, with more than 500 gallons of additional storage capacity on site, all of which is needed during the sap run’s peak.

The group’s de facto engineer, Swager rigged a siphon nozzle to the cooker that uses compressed air to force used oil into the firebox to create a hotter-burning fire.

Like a turbocharger, the nozzle boosted the cooker’s advertised burn rate from 25 gallons an hour to 35, with a smokestack temperature that hovers around 1,000 degrees.

In coming days and weeks, woman-, child- and manpower will be needed from all five families to keep the operation cooking at full capacity.

“Some years back, we kept a fire going all day and all night,’’ Swager said. “We generally don’t do that anymore. We might cook until midnight. Then we’ll take the fire out and flood about 10 gallons of sap into the flue pan and the syrup pan, and that’s what we’ll start boiling the next morning, with a new fire.’’

Throughout much of the syruping season, a party atmosphere will prevail around the cooker. This weekend, Steve Anderson will provide a feast of smoked ribs, and the group’s annual wiener roast will follow at a future date.

Ending the season, the group will gather in Swager’s garage to bottle the finished product.

“Pam has a wonderful waffle recipe that is mostly butter, and while we bottle the syrup, she’ll cook waffles, onto which we ladle the fresh syrup,’’ Swager said.

“Neighbors might wonder what we’re doing in the garage with steam coming out and waffles being cooked. But we get the syrup finished and bottled. Last year, we bottled 100 gallons in about nine hours.’’

Sweet.