CIMARRON — Imagine we are heading to an island, says Jim Aronstein.

“And this,” he says, stepping into a plush snowcat, “is our boat.”

Minutes later, he is relishing his island oasis, fat Rossignol skis sending powder billowing on a gladed slope he helped clear with his chain saw.

The matter-of-fact, retired natural-resources lawyer turns into a buoyant powder hound up in his 2,000-acre paradise on the northernmost tip of southern Colorado’s toothy San Juans. His grin widens with each effortless turn down north-facing slopes that spill from an 11,400-foot ridge that spans 2½ miles.

Aronstein loves undisturbed snow so much that it’s the foundation of his one-of-a-kind business plan. And preserving powder is positioned above profit as he plots to partition paradise.

“The constitutional vision here is to retain the wilderness character of the place and to make sure there is pretty much always good powder to ski on the mountain,” said Aronstein, 61, who this winter unveils his Cimarron Mountain Club — with a private ski area bigger than Aspen Mountain — as a home for only 12 deep-pocketed buyers.

“Sure, we want to recover our investment, but at the end of the day, the most important thing for us is to have a really great place — something my family will continue to participate in for generations and that will be a very special place for others as well,” said Aronstein, who has no debt on the ranch. “That’s really more of the reward here than a financial return.”

Aronstein bought the former logging company land above the Cimarron River, in the shadow of the turreted Cimarron Range, in 2005, the day after he and a partner sold nearly 6,000 acres of lawsuit-addled mining claims on the backside of Vail ski area to Florida developer Bobby Ginn for $32.75 million.

The ranch was a getaway for him, his wife and their three sons. They spent several years bouncing up rugged roads, fishing the property’s many ponds and marveling at the geology — including a basalt-fluted volcanic monolith not unlike Devil’s Tower.

And they skied. The timber company had carved open swaths on a couloir-draped ridge, and Aronstein and his boys would snowmobile up and down, skiing the deep snow. They thought about a chairlift. Then they thought about carving the property into homesites and sharing their powdery Eden.

“At the end of the day, we thought it would be nice to have some other people around,” Aronstein says.

But before he made a plan, Aronstein called a friend. John Norton, the former second-in-command at Aspen Skiing Co. and one-time boss of Crested Butte Mountain Resort, had gone to school at Dartmouth College with Aronstein. Four years ago, Norton visited the ranch with a plan to dissuade his pal from investing too heavily in a private ski area.

He was blown away.

Norton called a friend. Johnnie Stevens, the longtime Telluride ski area boss, came over with equal reticence. Stevens called Andy Daly, the former Vail Resorts executive who now owns Powderhorn near Grand Junction. And Bill Kane, the former planner for Aspen Skiing Co. and longtime principal of planning outfit Design Workshop who now serves on the Colorado Parks and Wildlife Commission, came by for a visit.

“Everyone had the same reaction I did,” Norton says. “There’s nothing out there like this place.”

Four of the Colorado ski industry’s heaviest hitters, longtime competitors in the cutthroat game of luring ski vacationers, joined Aronstein in a unique plan to open, but not quite develop, the sprawling mountain wilderness to like-minded buyers.

The board that directs the club now includes Eric Calderon, the Auberge Resorts chief operating officer who launched Aspen’s Little Nell Hotel, and Bobbie Burkley, the former vice president of marketing for Aspen Skiing Co. When that board gathers, it’s a Colorado skiing name-dropping bonanza.

“We put a lot of thought into this. It’s been a very dynamic process,” said Stevens, a 70-year-old skier who hung up his Harley leathers to come out of resort-chief retirement and join Aronstein as general manager of the club. Stevens, who captained Telluride for 33 years, calls the project “my swan song.”

Aronstein and his equity partner, Kim Koehn, listened to the board as they shaped a way to preserve the wilderness while sharing the land.

Aronstein, who won a breach-of-contract lawsuit against Vail Resorts in 2003 after the resort company balked at a prenegotiated plan for developing the Battle Mountain land he sold to Ginn, wanted a simple plan anchored in powder and wilderness.

“Something where we would really be able to have control over the vision and executing the vision,” he says. “It’s not about maximizing profit. It’s about maximizing the beauty of the area.”

The final concept — honed after more than three years of discussion with the heavyweight board and just now reaching the market — is unlike anything in the world.

The Cimarron Mountain Club divides the 2,000-acre ranch into a mere 12 parcels, from 35 acres to 204 acres.

Kane, one of the most respected planners in the resort industry, whittled the potential number of sites from a possible 50 35-acre lots to a dozen. No homesite is visible from another, giving each owner their own piece of remote wildlands. Site prices range from $2.7 million to $3.85 million. Electrical lines are plugged into each site and water is piped from the property’s bounty of springs.

All owners — as part of their annual dues of $50,000, or up to $90,000 for homesites split between as many as four families — get unlimited snowcat and guided skiing. All but one of the parcels is ski-in, ski-out, with a couple of the sites accessible only by talented skiers.

A groomed cross country skiing trail will roll across the property. Gunnison mountain biking legend Dave Wiens designed singletrack trails for summer that access each homesite. The club will offer some buyers communal trail horses and stables.

Most every site has its own pond. A planned clubhouse will anchor the property, with a restaurant, bar, spa, pool and gym. The clubhouse, a three-bedroom guest house, fishing cabin and parking sheds will be added once six homesites are sold.

And in a twist for potential buyers who share Aronstein’s passion for winter, access in the snowy months is by snow machine only. That means winter visitors will need the PistenBully snowcat, the trailer-towing, dual-tracked Alpina Sherpa snowmobiles or the side-by-side Polaris Tracker, or a Chevy Suburban outfitted with snow tracks to reach their homes.

Every time a new issue popped up during planning, Aronstein and his board turned to the original concept: Preserve powder and protect the wildness of the property. Paved roads? Won’t work with wilderness. More homesites? That wouldn’t deliver the lonely-cabin-in-the-woods vibe. How about a chairlift? That could destroy powder.

“There are a lot of things as you go that try to pull you in other directions,” Aronstein says. “You have to think through them, and it’s nice to be able to judge all these smaller decisions through the lens of the constitutional ideas.”

For five years, Aronstein, his sons, his ski guides and Stevens have carefully gladed the runs that spill from the ridge. Mike Larson, the founder of International Alpine design who helped sculpt 200 runs at Vail and its 500-acre Blue Sky Basin, guided their efforts. Aronstein originally named the runs after Jimi Hendrix songs. But his wife, Patsy, successfully lobbied for more conventional, historical names. Only “Watchtower” remains.

“I’d like to see ‘Voodoo Chile’ come back,” says Aronstein, who still calls some of the runs by the names he conjured while chain-sawing trees.

The area has about 60 named runs and another 20 planned.

On the south end of the ridge, beginner runs are groomed. Above those groomed runs, 13 steep, hike-to couloirs wind through near-vertical cliffs. On the north end, the runs get steeper, plummeting 1,600 vertical feet through glades of spruce, Douglas fir, lodgepole pine and aspen. A dozen more precipitous couloirs tumble off the property’s 11,453-foot Castle Rock peak.

Last summer, the crew loaded 45 tractor-trailers with timber headed to the Montrose sawmill.

“It’s as extreme as you possibly want to go,” said Will Aronstein, the 27-year-old eldest son, who has skied the area for nearly a decade, enlisting friends in summer-long chain-saw sessions in his younger years. “All these years skiing here and I’m still discovering new stuff.”

Aronstein’s team — which includes veteran ski guides and patrollers — has applied for an explosives permit for avalanche control. The mountain hosts — a husband-wife team of fishing guide Shawna Stephens and fish biologist Scott Slater — live on the property in an off-the-grid cabin, where they cure the elk and deer they harvest off the property.

A typical meal made by Stephens and Slater includes elk, venison and sushi made from trout caught that morning in a nearby pond.

Slater, a fish biologist, says the flesh on some of the trout he has found on the property is better than fresh salmon he has caught in Alaska.

Ski guide Kris Noel strokes his beard atop a run and tells a group of skiers this is “kind of an emotional moment.”

Everyone turns to him.

“I cut this run this summer. This will be the first time anyone has skied it,” he says. “I hope you like it.”

This isn’t a sales gimmick, Aronstein says later. The hosts, guides and club employees are believers in the wild nature of the property. They reflect the mountain culture he’s hoping to amplify at Cimarron Mountain Club.

“Everything you experience here is making you feel that mountain culture. Like ‘Yes, I am Jeremiah Johnson,’ ” Aronstein says.

That culture will play a role in “self-selecting” the clientele drawn to the club, says Aronstein, describing how he declined a Telluride billionaire’s offer to buy the whole place after the unnamed magnate visited with his security team, his own chef, and his own silverware and plates.

Aronstein likes to call his resort “the Un-Vail.”

That’s not knocking Vail. He has had a place there for many years.

“It’s just a different experience here,” he says. “The big resorts have a different culture than this. People want that wilderness experience. That’s what we are providing. We are offering that lonely-cabin fantasy, with all the support and the infrastructure and the recreation.”

Jason Blevins: 303-954-1374, jblevins@denverpost.com or @jasonblevins