When I was told the skiing in Colorado would be breathtaking, I didn't realise they meant it literally.
But when a sea-level dweller can take a chairlift to nearly as high as the summit of Aoraki Mount Cook, it only takes a few turns before lungs are screaming for mercy.
We've been brought to the highest point of the skifield by veteran ski instructor JT, whose 25 years at the twinned resorts of Winter Park and Mary Jane have earned him universal recognition by just his initials.
He's giving us a tour of the vast resort, but after more than two hours, it's clear we've barely scratched the surface – either of the skiing, or of JT's array of derogatory jokes about snowboarders.
We've skied groomed slopes as wide and smooth as a rugby pitch and we've passed the resort's trademark black-diamond mogul runs, where the passage of skiers has created a network of bumps that resemble dozens of VW Beetles parked in close formation.
There have been gentle beginner runs, and treed areas where the powder snow lasts.
But the really sobering part is that for each run we've been on in those two hours, there are at least another 10 we have yet to explore.
We had a hint of this with our first look at the trail map. Compared with the more modestly sized New Zealand ski areas, the profusion of designated trails – more than 140 of them – makes the map resemble a plate of spaghetti thrown at a wall.
The culinary analogy is apt. This is, I remind myself, the land of supersizing and it's true of the skiing as much as the food.
I used to think Whakapapa – with about 550 hectares of skiable terrain – was a mammoth resort. But Winter Park, originally developed in the 1930s as the Colorado capital's winter park, is bigger than that on its own.
The neighbouring area of Mary Jane is named after an enterprising 19th century hooker who gained land here through her, er, interactions with local miners, loggers and railroad workers.
It became part of the resort in 1975, and is the home of steep bump runs which inspire the slogan "No pain, no Jane".
Then there's Vasquez Cirque, an ungroomed but avalanche-patrolled zone with no easy or intermediate terrain and 83 per cent of the runs graded "most difficult".
Together, the three sectors of the resort are nearly three times the size of Whakapapa, but even this isn't the biggest skifield in Colorado.
There are lots of supersized stats about the resort, but the ultimate one is the look on our faces as JT shepherds us onto the Panoramic Express chairlift – the highest six-seater chairlift in the United States.
From the top, at about 3670 metres, we can choose to ski all the way to the base area along a route eight kilometres long and dropping 950m.
At the top of the chair, the noticeboard is advising that the temperature is -25 degrees Celsius. It's accompanied by a blustery breeze that tests the capability of our ski gear.
We head straight down towards the shelter of the trees. After a couple of stops on the way to gasp for breath and let my quads recover from the exertion, I arrive to hear JT explaining to others the difference between a vacuum cleaner and a snowboarder: "It's where you attach the dirtbag."
After three hours, JT sets us loose and we head for Sunspot, a mammoth timber and stone building which houses a cafeteria, a bar and an upscale restaurant. Yet more fodder for the supersized theory.
During the next few hours, I use chairlift rides to grill other skiers about what makes Winter Park stand out. "Bumps," one says. "Definitely the bumps. And the trees."
Finally, I find something that isn't supersized. It turns out that for the past 10 years or so, thumb-sized bark beetles have been devastating the lodgepole pine forests that dominate this part of the Rockies. One theory holds that the beetles are a harbinger of climate change – they thrive in hotter, drier summers and milder winters.
Whatever the cause, a fungus spread by the beetles is the reason why many of the evergreens are a sickly brown.
But that, in turn, is good news for skiers. Eventually the dead trees will rot and more open and user-friendly slopes will appear.
For the rest of the day and the ones that follow, we try Winter Park's smorgasbord of skiing: packed powder above the treeline, pockets of fresh powder among the trees, corduroy-like groomed slopes and even some knee-punishing bumps on the black-diamond mogul runs.
Afterwards, I'm as knackered as I can remember being on a ski trip, beaten down by attempts to match the scale of the resort. It's a good knackered, though – as you'd expect skiing in the land of supersizing.
If there's anything that can make the sumptuous spa at Devil's Thumb Ranch even more inviting, it's having spent a few hours blasting around the backcountry on a high-powered snowmobile.
Several hard days pounding the powder at Winter Park had left us hankering for a day off skiing.
In any group there's always a dilemma between petrolheading or pampering, so we were chuffed to find we could do both without leaving the valley.
The snowmobile tour operator, Grand Adventures, is based on the hills across the river from Winer Park and uses a maze of forestry roads that lead up to the continental divide that separates the Pacific and Atlantic watersheds.
After gearing up for the Arctic weather, we met our guide, "Ampa" Cook, whose grandfatherly way soothes the nerves of those who have never ridden a snowmobile.
I'm one of the neophytes, but it all turns out to be surprisingly easy and soon we're climbing past an abandoned railway trestle above the tree line towards the crest of the Rockies.
The views up here must be magnificent on a clear day. For us, the weather is coming in, so we retreat into the forest on single tracks between the trees.
Adding to the weariness from hard skiing, we're looking forward to Devil's Thumb Ranch, a 2000-hectare property just down the valley in Tabernash. It's owned by a Denver couple who have developed the ranch more as a hobby than as a money-making proposition. The attention to detail is gobsmacking, with a mammoth main room of stone and timber.
That philosophy continues with the Ranch Creek Spa, located in a separate building.
In one of eight therapy rooms, I'm soon face down on the massage table, wondering if the bowl below my face is intended to catch my drool.
"Ah, no," my masseuse responds, more tactfully than my question warrants. She fills it with boiling water to provide a rising plume of aromatic steam.
An hour later I'm blissed out and sitting back on the couch, wondering how I ever felt sore or tired from the skiing, and again raring to hit the slopes again in the morning.
Day lift passes were US$97 a day this season but an advance-purchase season pass for next winter, including some neighbouring resorts, is on sale for US$409 until April 10.
Accommodation and ski pass deals are available via NZ wholesalers.
Grand Adventures snowmobile tour:
A two-hour tour to the continental divide is US$100.
Devil's Thumb Ranch:
A 50-minute aromatherapy massage is $115. Accommodation at the lodge ranges from a bunkhouse with shared bathroom to rooms in the main lodge and cabins nearby.
Air New Zealand flies direct to Los Angeles and San Francisco daily (SFO five times a week April to December), with return fares starting from $2366 per person.
For more information and deals on flights, accommodation and travel insurance visit airnewzealand.co.nz call 0800737000 or visit an Air New Zealand Holidays Store.
The writer played in the snow courtesy of Colorado Ski Country, coloradoski.com.
- The Dominion Post