A new breed of fish house has all the comforts of home. Photo: Michael Hehner/Lindner Imagery for The Wall Street Journal.

When Dennis Larson went ice fishing with his buddies on frigid Lac Qui Parle Lake in western Minnesota one recent weekend, he brought his jigging rods, rattle reels and a power auger for drilling through three feet of ice. He also brought two, 32-inch flat-screen TVs, a poker table and a blender for mixing strawberry daiquiris—just a few of the amenities in his new, 30-foot-long Ice Castle fish house, which he drove right onto the lake. He plans on spending most weekends there through February.
"It doesn't matter how cold it is outside—it's like being home, only you're able to catch fish," said Mr. Larson, the 58-year-old owner of a contracting company in Montevideo, Minn., describing his $44,000 custom shanty.

Illustrations by Kerry Hyndman
After checking with a local fishing guide that the ice was solid enough to support the 6,200-pound house, he hitched it to his pickup truck, drove to his favorite fishing spot and lowered it to the ice on a built-in hydraulic lift with the touch of a key-fob. He then drilled through 10 openings in the floor, set up his reels and began his fishing trip in the great indoors.
Ice fishing, a traditional winter pastime in northern states and the Great Lakes region, may conjure up images of grumpy old men in flannel hats sitting on buckets. But the sport has boomed in the past decade, its popularity fueled by the development of high-performance gear and technological advances such as sonar fish-finders, underwater cameras and lake-mapping apps for smartphones. In Minnesota—where ice fishing is less a sport than a cultural institution—the homemade wooden shacks that once dotted frozen lakes are being replaced by increasingly elaborate and expensive shelters, snug enough to withstand a polar vortex and loaded with electronics.

Slide Show: Whopper of a Fish House

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Dennis Larson uses an underwater camera and sonar to find his catch. Michael Hehner/Lindner Imagery for The Wall Street Journal
Though compact enough to be towed on a highway, Mr. Larson's new shack boasts a kitchen with an oven, microwave and refrigerator, a full bathroom with a heated shower and a skylight, couches that fold out into a king-size bed, a stereo system with built-in speakers and a pop-up dome satellite dish for catching Sunday football. A fireplace tucked in a cozy alcove between a set of bay windows casts a glow on the tongue-and-groove cedar-paneled walls and ceiling.
The 10 fishing holes are carved right into the floor. Built-in holders for Mr. Larson's rods and rattle reels (named for the sound they make when there is a pull on the line), allow him to fish while he mixes cocktails at the countertop bar, or plays a hand of poker. An underwater camera hooked up to the televisions shows the crappies and walleyes swimming directly underfoot, while a sonar display gives their depth and finds fish out of camera range. Bait minnows swim in an illuminated aquarium built into the wall, powered by an automatic pump that draws fresh water from the lake; a second tank holds the day's catch.

Mr. Larson's tricked-out fish palace was made to order by Ice Castle Fish Houses, one of a number of regional manufacturers riding the fancy fish-house trend.
Jeff Drexler, whose American Surplus & Manufacturing in Montevideo, produces the top-selling brand, was making portable storage units when one of his dealers asked him to build a fish house in 1997. "Before we even got back, they had it sold," said Mr. Drexler. In 2013, the company sold 2,081 fish houses, he said—up from 1,422 units in 2012—grossing $23 million. This year he is projecting sales of 2,500 units.
Thomas Walworth, president of Statistical Surveys, a marketing-research firm that tracks the sales of recreational vehicles, has seen "a dramatic increase" in demand for these portable fishing shacks since 2007, when his firm began collecting data on them. "The industry started to look at them and see there was quite a lot of market," he said. Now, leading RV makers such as Forest River are getting in on the action, with its Salem Ice Cabin line.
Designed for stays of several days or longer in subzero temperatures, high-end fish houses have spray-foam insulation, double-paned windows and forced-air furnaces. They also have air-conditioning units: Most are now built to double as hunting cabins, which may explain why curtains and upholstery tend to be more "Field and Stream" than "House Beautiful."
"I have five different patterns, all camouflage," said Eric Bongard of Custom Cottages in Shakopee, Minn.
That appealed to Jeff Douglas, a 46-year-old nurse in Andover, Minn., who spent close to $50,000 on a 24-foot Custom Cottage that sleeps six to use year-round for ice-fishing and hunting. In addition to a gun closet, his "toy hauler" model features a back end that drops down into a ramp so he can wheel his two all-terrain vehicles inside. Mr. Douglas can use an all-terrain vehicle to tow his 5,500-pound cottage onto early-winter ice; made entirely from aluminum, it's lighter than steel-framed models.
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The interior is smartly organized, with overhead racks for fishing rods and a queen-size bed that lowers from the ceiling on electric jacks. A generator—a must for deluxe fish houses—helps power Mr. Douglas's multiple TVs, DVD players and underwater camera.
Although there is no running water, the house has a bathroom with a portable toilet—and its own fishing hole. "We had the best luck out of that hole this weekend," said Mr. Douglas, who had just returned from a fishing trip with his wife and three children to Upper Red Lake in northern Minnesota.
Owning a house with so many holes in the floor has its pitfalls. Small children—and adults on nighttime trips to the bathroom—have been known to step in them, plunging waist or thigh-deep in icy water. (Since fish bite at night, most people like to leave the holes open.) Car keys, cellphones and wedding rings have vanished.
"Whatever you can drop, it goes down the hole," said Mr. Douglas, who forgot to bring catch covers—screens that fit over holes with fishing lines—on his trip with his kids. "I was so afraid they were going to drop the TV remote down the holes, I changed the channels myself," he said.

Occasionally, the houses themselves take a dip. "I personally had one go through," said Chad Hiepler, Ice Castle's office manager, recalling how an unseasonable warm spell 12 years ago loosened the ice on a local lake enough to send his house and many others pitching into open water. "I got a bunch of buddies together, we were able to winch it out," he said. He advises Ice Castle owners to take out insurance.
These new fish houses on wheels are designed for lake-hopping, to be towed wherever the fish are biting. Traditional shacks, known as skid houses, are set on ski-like runners. Once they are dragged onto the lake, they stay there for the season.

Every winter, entire shantytowns spring up on the ice of 207-square-mile Mille Lacs Lake in central Minnesota, the state's ice-fishing epicenter. Many return annually to their favorite resort—lakefront areas maintained by individual owners who monitor ice conditions, plow roads, rent out fish houses and come to the assistance of fishermen who can't find their way back to their shanties after one too many adult beverages on shore.
Cathie Kranz, a 54-year-old executive assistant from Prior Lake, Minn., enjoys the sense of community at George Nitti's Hunters Point Resort, where she has been ice-fishing for years. In 2011, Mr. Nitti built her a $27,000 skid house that she helped design.
"I wanted it to be a place where people could come and feel comfortable," said Ms. Kranz. "I didn't want it to be too manly—I want it to feel clean and fresh."
The 12-by-22-foot pine cabin is airy, with a cathedral ceiling, fan lights and large windows. It exudes a certain icehouse chic. A tiny antique sleigh hangs on a wall near a 42-inch TV in the full-size kitchen, where Ms. Kranz has prepared roast turkey and prime-rib dinners.
The custom-made cabinets and drawers have handles shaped like walleyes, and there is a whimsical assortment of fishing poles in the bathroom, which is decorated with a light fixture that resembles a pair of jigging rods. It doesn't have running water, but there are outlets for Ms. Kranz's hair dryer, flat iron and makeup mirror.
Over at a neighboring resort owned by Eddy Lyback, who patrols his patch of frozen lake in a beaver hat from the wheel of a 1966 Ford pickup, roads are marked by hand-painted signs. John Kalina, a 59-year-old farmer from Lonsdale, Minn., parked his new 34-foot aluminum-sided wheelhouse on the Bowl, named for a dip in the lake bottom. A sleek 8,400-pound behemoth with a giant walleye decal, the house was built by a nephew and by his 27-year old son Jeff, who estimates that it cost just under $55,000.

Paneled entirely in water-resistant cedar with a seven-foot vaulted ceiling, the house has a large bay window, handsome knotty-alder cabinets and a 40-inch television. Bright LED lights on the exterior guide Mr. Kalina back home in the dark; pathway lights on the carpeted floor inside insure that he won't trip in any of the eight fishing holes. Magnetic sensors in the reel holders trigger a buzzer or play a lively polka tune when there is a tug on a fishing line.
There wasn't much music that weekend: Mr. Kalina had yet to catch a fish in his new house.
"I don't care," he said. "As long as I can get it out on the ice, I'm satisfied."