Emerging in the Minnesota spring are a flush of morels — and those who hunt them.

Retired naturalist Ron Spinosa has hunted morels for three decades all over the state and into Wisconsin.

But the Minnesota Mycological Society's resident identification expert had one of his most memorable encounters in a south Minneapolis backyard.

"I got a phone call from a woman who said, 'I've got these weird mushrooms coming up in my backyard. I think they might be morels, but I don't want to try them without knowing,' " he said.

When he arrived at her house, Spinosa saw a recently cut elm stump and morels in all directions.

"There were morels coming up around her drain spout, among her tulips. It was pretty incredible," said Spinosa, of St. Paul.

When the snow retreats and the Northland wakes up each spring, when leggy shoots begin to uncurl above the mat of old leaves, morel hunters, like Spinosa, get the itch to be out in the woods.

"There's a buzz in the air, telling you, 'It's time, it's time,' " said Kathy Yerich, of Forest Lake, a local video producer and fellow member of the group with a special interest in fungi. "I think you can almost smell them in the air."

Out of the dead ground, suddenly, there's abundance. A carpet of bloodroot, Dutchmen's breeches and false rue. Mayapples unfurling like woodland umbrellas. And here and there, in the right conditions, a flush of yellow or black morels.

"One of the reasons people like morels is that they're spring mushrooms," Spinosa said.

"Especially in the Upper Midwest with long winters, when the trees start to bud out and the lilacs bloom, people just want to get out."

For many, morels are the "gateway mushroom," Spinosa said, the one that gets people in the door.

They're also one of the easiest for first-timers to identify, with their distinctive honeycomb shape and their short fruiting season in the early spring.

Outside of public forays, morel hunters are notoriously secretive about their best spots.

"There's a certain mystique about morels. People will keep their spots closely guarded; they will barely tell their close friends," said Yerich, who co-authored a guidebook called "Mushrooms of the Upper Midwest."

"I'm not a morel hound. And I would give them away, but I'm a little protective of my morel spots."

In decades of morel hunting, Spinosa said he's noticed it's getting more difficult to find them on public lands.

Many county and regional parks in the metro area don't allow mushroom hunting. Those that do, including state parks and wildlife management areas, are seeing more traffic.

Yeng "Luke" Thor of White Bear Lake learned to forage from his parents and has been hunting for oyster mushrooms for more than 25 years. In the spring, he often spends long days in the woods, hunting for fiddleheads, asparagus and watercress.

A Wisconsin friend, who knew he hunted mushrooms, showed him how to find morels.

"When people say, let's go hunt, I say, no, you can't just pick a place and search for it," said Thor, a machinist. "You have to do your homework. You have to study the area to know if it is going to produce. If you don't, you're going to waste your time."

Thor learned from his friend to look for moist, shady areas, with a covering of leaves. He also pays attention to the weather.

"If it's too hot, they're not going to grow. We need at least 55 to 60 degrees, a straight shot, and then cloudy with a little shower here and there, and I will guarantee the next day you go they'll be out," he said.

Spinosa said dead elms are "morel bonanzas" in central Minnesota, but they have been spotted around ash, cottonwood and many other trees, depending on the soil and region.

A good spot around a dead elm will fruit for three years — five at the most, Spinosa said.

"I'm always looking for new spots," he said.

For some morel hunters, the season can't start soon enough.

Alexandra Schulz, a local mushroom guide and special education resource teacher, said she was hooked by her first morel encounter.

"I saw a tree on its side and spotted a yellow morel, and then they were everywhere," she said.

During morel season, which usually runs from mid-April to mid-May in the Twin Cities but is later this year, the Minneapolis woman goes out every night. She also hunts for morels all day on weekends.

After tracking the northward march of morels via Facebook in recent years, she has started driving to Missouri and Iowa for early-season morel hunts.

This February, she and her boyfriend drove through a blizzard to get to Missouri.

"There's no way I can explain to my parents why I'm driving to Missouri at 2 a.m.," she said, laughing. "It's a way to accelerate the spring."

At first when she posted pictures of her mushroom finds, she worried it would seem too "hipstery."

Now, she sees peers who had no interest in the outdoors posting about their own first morel discoveries.

"It's great that more people are getting out in the woods," she said. "Our society is still so mycophobic in so many ways."

Spinosa said the explosion of wild mushrooms at local restaurants and farmers markets has spurred interest in morel hunting.

"It's fun to go looking and get outdoors," he said. "If you find one of those mother lode spots, it's just so exciting."