T'was the night before Christmas, and out in the snow, we gathered by moonlight, all ready to go. OK, so maybe not that ready. Some of us were having problems with our snowshoes. Jen and Tammy, our instructors, took it in their effortless, loping stride, tightening buckles, twiddling ski poles to the correct height. Feels strange at first, they assured us, but it's very easy when you get the hang of it. Just like walking, only you float up on the snow. Ready?
Stumbling and breathing heavily, we were off, leaving behind the cosy confines of the Tamarack Lodge to venture out into the winter wonderland of the Californian Sierra, at the foot of Mammoth ski resort.
The best thing about heading to the mountains at this time of year is that it frees you from the tyranny of Christmas, and leaves you to enjoy all the good bits. You know, the bits people write poems and songs about - snow and pine trees and sleigh bells and laughter. Instead of a day of last-minute panic-buying, the scent of defrosting turkey and that creeping sense of desolation as everybody leaves town, we'd spent Christmas Eve on the slopes, whooping and hollering past skiing Santas and happy kids.
Now the rest of them were tucked up in our condo on the slopes, not exactly dreaming of sugarplums but downing margaritas, which is practically the same thing. And I was tripping over the hi-tech tennis rackets strapped to my feet, waddling out under a full moon into the deep and crisp and even.
Ahead of us was a family from LA, the two teenagers putting stomping distance between themselves and mom in her Christmas sweater behind, a group of young guys from Minnesota. One couple from San Diego were on their annual Mammoth Christmas trip; another, clenched in a semi-permanent embrace, were newlyweds. Taking full advantage of California's geography, they had got married on the beach just two days before, then driven five hours up the road to honeymoon in winter. Only Dave was out on his own, his wife preferring to spend the evening back at the lodge, in front of the fire. "I don't do cold," she explained, later, grinning brightly through her Orange County permatan.
By the time our little group had found their feet and climbed up to the Tamarack cross-country ski trails, I was stepping on my shoes less often and the hot sweat of starting out had subsided to a pleasant radiating warmth. And oh - the moon on the breast of the new-fallen snow really did give lustre of mid-day to objects below. "We never need to use lights," said Jen, as she leant on her ski poles and gazed at the impossibly perfect groomed tracks, sparkling brightly at our feet. "We run one full-moon cross-country ski trip and two snowshoe treks per month, November through February, and it's always bright enough - so long as it isn't stormy."
Onwards and upwards, winding along a dusky pathway through evergreens and out into a wide-open area beneath the rocky mass of Crystal Crag. "This is the old Mammoth mines area," explained Jen. "You can still see the ruins in the summer."
We crested a small ridge, and the world fell away. Far below, the Long Valley caldera stretched away to the east, pinpricks of light dancing from the few homes of those hardy enough to live on the stark, snow-dusted volcanic plain. Through the trees to the north, the town of Mammoth Lakes was blazing with holiday cheer; behind loomed the pistes, busy with Snowcats preparing for the Christmas hordes.
And above? Above was the cold, clear sky, moon and stars twinkling quite as brightly as on any glittery charity card. Eight hours away east, across a cacophony of midnight masses, under those same stars, the smallest of my loved ones were already stirring under the weight of stockings on their beds. The shared sky made the missing of them all the sweeter, and sent the festive cheese-o-meter off the scale; I don't think that I'd felt this genuinely excited on 24 December since I stopped believing in Santa Claus.
The trek back to the lodge was suffused with a feel-good glow, as our group headed towards Christmas Day - and, more immediately, to the cheesecake and hot eggnog waiting in the wood-panelled lodge. By now, the newlyweds were almost in each other's pockets; even the teenagers let up their pace, strolling along happily beside their parents.
Then all of a sudden: commotion. What to our wondering eyes should disappear but Dave, who dropped abruptly out of sight.
"Um..." came a voice from snowshoe-level, as we were still registering his absence. "I appear to have fallen down a hole."
His head was level with the ground, chin resting on the snow; his body fit the peculiarly square hole perfectly. Hands reached down to scoop him out - he was barely grazed, but slightly stunned. We all peered back into the earth, lighting the depths with our phones and gazing at the tangle of briars and roots that had caught his snowshoes and broken his fall.
Unexpectedly, for a group leader who had just almost lost one of her party, Jen was trying very hard not to laugh. "That's not a hole," she said, her eyes twinkling. "We're above the ruins of the mining village. I believe that's a chimney."
And so our night before Christmas drew to a close, according to the script, though Saint Nic was an ordinary old Dave, and he fell down the chimney rather more ignominiously than the jolly old fellow of the poem. Still, he was very good spirited about it all, and accepted his new role quite happily, regaling his wife back in the lounge with tales of our adventure.
He may have even exclaimed, as we drove out of sight, "Happy Christmas to all, and to all a good night." At least, I like to think that he did.
With lines taken from Clement Clarke Moore's poem 'A Visit From St Nicholas'
The nearest airport is Reno/Tahoe, a three-hour drive from Mammoth Mountain. While there are no direct services from the UK, connections are available from Los Angeles with Southwest Airlines (001 800 435 9792; www.southwest.com). Los Angeles is served from Heathrow by British Airways (0870 850 9850; www.ba.com), Virgin Atlantic (08705 747 747; www.virgin-atlantic.com), United (08458 444 777; www.unitedairlines.co.uk) and Air New Zealand (0800 028 4149; www.airnz.co.uk); US Airways (0845 600 3300; www.usairways.com) flies from Gatwick.
Tamarack Lodge, Mammoth Mountain (001 760 934 2442; www.tamaracklodge.com). Cabins start at $151 (£84), self-catering; lodge rooms start at $90 (£50), room only.
Full-moon snowshoeing tours in 2007 are scheduled for 1, 3 and 31 January; 2 Feb and 1 and 3 March. The cost is $35 (£19) per person, including all equipment and post-trek drink and dessert, and they can be booked through Tamarack Lodge.
Mammoth Mountain, California: 001 760 934 0745; www.mammothmountain.com