On a Midwestern road trip, a writer zigzags from one small-town café to another in search of spectacular pie. Here she extols her favorite discoveries and the bakers behind them—some sweet as peaches, others tart as rhubarb.

The question had already gotten me blank looks from several convenience-store clerks. So when I asked the old-timer running a hardware store in McGregor, Iowa, where I could find local fresh-baked pie and he blinked and slowly stroked his fleshy nose, I figured he wasn't going to be helpful either. But just as I was about to head out the door in frustration, he said, "Oh, wait! I seen a sign over in Prairie du Chien by the Hungry House saying they got pie." Forty minutes later, after crossing the Mississippi River into Wisconsin, I was cutting into a slice of fluffy, eye-crossingly rich sour-cream-raisin pie at the Hungry House Café, where a sign outside says PIES R US in wobbly plastic letters. Meanwhile, retirees and young families in neighboring vinyl booths sensibly ate bacon and eggs for breakfast.

Last summer, I somewhat reluctantly moved back to my hometown, Milwaukee, after 12 years in New York City. One thing I'd missed was the great pie we always had going for us in the Rust Belt, so I decided to zigzag up and down two-lane rural roads from one small-town café to another and sample fresh, homemade pies with lunch, dinner and breakfast. The last time I'd made such a pie tour was in 1996, when my waistband grew so tight I had to institute the "original-signage diet." (I would stop only at places with rickety old signs; still, there were plenty of those.) But this time, even after two full days on the road, no such diet seemed necessary. Many of the cafés where I'd eaten pie before were now closed, faded FOR RENT signs in their dusty front windows.

That's why the Hungry House Café—with its sparkling refrigerated display case of fruit and cream pies—saved me. After I polished off the sour-cream-raisin, my waitress took me to the kitchen to meet the owner, Connie Riebe, a no-nonsense woman of about 50. Riebe told me a bit about her place (in business almost two decades, name stolen from an Oak Ridge Boys song, some 20 pies on the menu) as she gently stirred plump, cooked blackberries in a bowl. Riebe said she'd picked the berries in her backyard the night before, and she showed me the scratches on her muscular arms to prove it. She spooned two berries out of the still-warm, midnight-red filling for me to taste: "Ach, no one will notice!" They were sublimely sweet and sour, bursting with juice. Then Riebe poured the mixture into a store-bought graham-cracker crust. I couldn't help blurting out, "Don't you use homemade pie shells?" Riebe explained that after she and her husband expanded the place a few years back, it "just wasn't economic" anymore to make her own crusts.

When Riebe checked on two turkeys and a beautiful meringue pie all baking simultaneously in three ovens, I could see her need for efficiency. But how did she get her meringue to produce such nice, stiff peaks? Riebe pulled a tattered, coverless cookbook down from a shelf: The Prairie du Chien Memorial Hospital Cookbook. "It says to mix in a tablespoon of cornstarch," she replied.

After saying goodbye to Riebe, I drove west again, across northern Iowa, taking in the scenery along State Highway 9: an extended family of concrete deer on a front lawn; a skinny, shirtless boy attempting to fly a kite off the end of a fishing rod; an ancient, precariously canted barn about to stumble to its knees. By the time I found the town of Okoboji and the O'Farrell Sisters restaurant, a white clapboard house on a skinny road snaking around the shore of Lake Okoboji, it was four o'clock, and the restaurant was already closed. When I put my face up against the window, I could see an old-fashioned slide-top Coca-Cola cooler behind a curving 1940s linoleum counter—and a light still on in the kitchen. So I went around back and introduced myself through the screen door to the proprietors, 59-year-old Charlotte Sarvie (née O'Farrell) and her older sister Joyce Gapinsky, who grudgingly let me in. They gave me the only remaining pie they had on hand, slices that were slightly crumbled or a sliver too small to sell. Despite my best efforts at restraint, I finished every bite of the strawberry-rhubarb, the cherry and the Kit Kat cream (made with crumbled Kit Kat bars).

At first, the two women went about their business—Charlotte wiping down their already immaculate kitchen and Joyce leaning against the counter, cigarette in hand—without paying me much mind. But after they saw the obvious pleasure I took from their pie (particularly the strawberry-rhubarb, with its fresh, nubby filling), they warmed up. Charlotte told me that she and Joyce (and their two other sisters) had all started working at age 12 for their aunt, Edna Mae O'Farrell, who'd opened the restaurant in 1947 in another location. "Edna Mae was always hollering 'Pay attention! You'll be doing this someday!'"—which was how they learned to make the pies (which normally sell out by noon) and pancakes that have this place doing brisk business from April to October.

Joyce told me she used to make the crusts herself and rattled off the ingredients—"flour, sugar, water and lard"—but now that she's "slowing down a bit," she uses Pillsbury's. Charlotte let me in on a much darker family secret. "You want to know how we get our rhubarb?" she asked, leaning toward me conspiratorially. "We got Bob the trooper bringing it to us from the roadsides—so he can be sure we keep making rhubarb pie."

My yearning for a great homemade crust was finally satisfied the next morning in the nearby town of Spencer. I was poking through piles of 1930s feed-bag cloth in an antiques store called Grantiques when, out of the corner of my eye, I noticed a gorgeous apple pie at the front counter, where the proprietor brothers, Ric and Mike Patrick, also operate a coffee bar. The pie was still warm; the walrus-mustachioed Ric informed me that he'd taken it out of the oven only an hour earlier. It was attractively lumpy, with chunks of Braeburn apple, their skin left on, the juices cidery, the homemade crust browned and melt-in-your-mouth buttery. I asked Ric who taught him how to make this rustic pie, which reminded me of the ones you see cooling on windowsills in cartoons, steam drifting from knife slits in the crust to tempt any critter within sniffing distance. "My mom," he said, a note of irritation in his voice. "Who else?"

According to Ric, it should go without saying that anybody around here with any culinary skills inherited them from an older relative—typically of German, Irish or Scandinavian descent. (His mother was German and Polish.) The slightly rough-around-the-edges vibe of Grantiques—a kind of kaffeeklatsch headquarters for men's men—broke the gingham-tinged stereotype of what a pie place should be. After overhearing our conversation, a customer who'd stopped in for coffee asked me if I wanted to step outside and see the new cookbooks he had in his motorcycle saddlebags. But since that sounded like a scenario my dad once cautioned me to avoid (the motorcycle part, anyway), I politely declined.

That slice of pie had to tide me over for most of the day. As I left Iowa, I found that southwestern Minnesota's pie joints had been particularly hurt by the proliferation of freeway fast-food joints. Interstate 90 and its microwave-burrito-and-pocket-pie rest stops, cutting a straight path across the bottom of the state, appeared to have taken out the old cafés in a string of nearby farm towns with sharpshooter precision. But when I got farther from the interstate, veering northeast along State Highway 60, I found myself entering big pie country again. In St. James, I discovered not one but two small cafés serving very good pie: the Hometown Cafe, a sunny cafeteria where the peach pie was bright and slightly tart and, interestingly, I noticed, the senior citizens sat at long, sex-segregated tables, just like in seventh grade; and down the street, the Crescent Cafe, a narrow, wood-paneled place, where owner Deb Tierney's rhubarb pie—with a tender crust that broke into light flakes—schooled me to the hard truth that lard, which I'd always shunned in my baking, can be a key ingredient of great pie dough.

When I complimented her pie, Tierney, a slim, blond, 43-year-old, fetched her grandmother's 1938 The Household Searchlight Recipe Book, the source of many of her recipes. (She hires an 86-year-old baker to make the crusts.) As I leafed through it—the spidery marginal notations reminding me of my own grandmother's cookbooks—Tierney turned back to what she'd been doing when I came in: playing a game of video solitaire at one end of the bar. I told Tierney I was surprised she cooked so many things from scratch. "People come in here and are impressed because the noodles in the chicken noodle soup are homemade," she said, poking at cards on the screen. "But I'm like, 'Yeah? Big deal.'"

A bit farther along the road, I came upon a pie place near Rapidan that left me feeling even more relieved about the state of pie in Minnesota. The Dam Store, a tiny wooden cottage across from a lush park beside the Rapidan Dam, sells bait and burgers in addition to pie, which is often sold out by late afternoon. When I arrived, at six o'clock, all the fruit pies were gone, and they must have been great ones, because people coming in the door would look at the whiteboard menu, now down to just two pies—coconut cream and sour-cream-raisin—and clench their fists, hissing expletives under their breath. I ordered a slice of coconut right away so I'd have it when I finished my burger. And a good thing I did, because it was like eating the world's best-tasting cloud, topped with toasted coconut shavings, on a crumbly, slightly salty, shortening-based crust. Thirty-one-year-old Jenny Barnes, whose parents Jim and Linda Hruska have been running the place for 30 years, told me that two years earlier she'd started apprenticing with Erna Lange, the 93-year-old woman who'd been making pies for her parents for years. Last summer Barnes took over the baking herself. Her friends think she's nuts to get up before dawn every morning, but her customers tell her "Keep on baking." I told her the same thing.

When I asked Barnes for the secret to good pie crust, she shrugged. "You just cross your fingers and hope they come out. If not, you start over." She looked at me uncomfortably, shifting her weight from one foot to another. "Is that all you need to know?" Laughing, I told her, yes, thanks. Happy to see the art of Midwestern pie-baking catching on with at least one member of the next generation, I paid my check and hopped in the car, ready to head home.

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Louisa Kamps, whose last piece for Food & Wine appeared in December, has written for Elle and the New Yorker.