Ski Colorado: The biggest apres-ski party in Aspen can be found at Cloud Nine

It's three o'clock in the afternoon and I've never seen anything like it. We've barely finished our main courses over lunch at Aspen Highlands' legendary Cloud Nine Alpine Bistro when all 130 diners inside down knives and forks so they can boogie to the beat of George Michael's Freedom. Desserts are forgone for disco.

The change is so sudden I swear a switch has been flicked. One minute they were all tucking into hearty winter staples and the next every one of them is balancing on tables and chairs and filling every available aisle space they can find. Hips gyrate and arms flail as the resident DJ plays a succession of boot-tapping tunes routinely punctuated by the staccato popping of champagne corks. Drinks waitresses navigate paths through a mosh pit of rosy-cheeked skiers and snowboarders hell-bent on getting their groove on for as long as the fun lasts.

Many, like us, have earned the right to let their hair down. We've spent the morning "hiking the bowl", a rite of passage involving a 45-minute foot slog to the 3800-metre summit of Highland Peak followed by some of the steepest in-bounds skiing found in Colorado. That hike, in cumbersome ski boots, and along a perilous ridgeline above chutes reaching gradients of up to 48 degrees, would have left plenty here feeling lighted headed. But it's not the dizzying altitude or exposed pitches that are affecting them; they're woozy from boozing.

Cloud Nine has been described as the most hedonistic bar on any ski slope in the world. First-time visitors to this ritzy alpine town west of Denver consider a 2pm lunch reservation one of Aspen's must-dos, with some enjoying the daily ritual so much they return again and again. Part of the appeal is its location – 3300 metres up the mountain, inside a former ski patrol hut – and it's from the hut's days as a rustic emergency outpost that its decadence sprung.

Aspen Highlands first opened in 1958 as Aspen's fourth skiable mountain. Battling against the established Goliath that is the Aspen Ski Company – owner of the Aspen, Buttermilk and Snowmass resorts – Aspen Highlands' entrepreneurial proprietor Whip Jones was forever formulating ideas to entice skiers onto his slopes, so much so that it became known as the party peak.

The ski patrol hut had always served rudimentary snacks washed down by chilled beverages and the number of revellers taking part escalated over the years. Cheerleaders and students on spring break converged here in the 1970s, and stunts like ski patrol members jumping over the hut in front of hundred of cheering spectators became a daily event.

When the four mountains eventually consolidated under a single corporate umbrella in 1993, skiing the expert terrain around the Highlands Bowl became ever more popular. To be closer to the action, a new ski patrol hut was built higher up the mountain in 1998, and a year later an Austrian chef named Andreas Fischbacher became manager of the old hut, renaming it Cloud Nine Alpine Bistro.

Fischbacher immediately began transforming Cloud Nine into the sort of Tyrolean-style bistro he remembered from his childhood days in the Alps. The interior walls were demolished to create a more usable space and he started serving three-course meals in a more formal setting. It wasn't long before skiers required reservations to sit down and eat.