It's 9:30 a.m. when the lift operator starts the cable car, and then we're hanging in the sky, moving up so fast that our ears pop before we have a chance to swallow. We rise above windblown snowfields, past rock outcrops, and finally into the clouds before the surreal telescope domes of Pic du Midi's observatory appear. They cover the entire mountaintop, the metal glistening in the sun.

Fog in the French Pyrenees has kept me waiting five days to ski the steeps of 9,439-foot Pic du Midi. I've begun to doubt that the mountain even exists—until its intimidating flanks come into view.

That I'm here at all is surprising, because the Pic has long been the exclusive territory of astronomers. Local guides lobbied town officials for years to open the mountain to skiers, using the astronomers' cable car for access, and finally in 2002 the Pic du Midi association of towns opened this icon of the Pyrenees to experts accompanied by an instructor or guide. The easiest—and most popular—runs are on the south face, above the Bareges and La Mongie resorts, which surround the base.

Near the summit, I look out over the impressive panorama of jagged peaks from the observatory's terrace. My guide, Stephane Delpech, remarks that the Pyrenees "do not get the proper respect like the Alps do, but wait till you ski them!" He smiles as he points to the 45-degree Poubelle ("Trash Can") couloir, barely wide enough to fit a pair of skis sideways. We climb past the fence behind the observatory and boot up a few more feet between domes and satellite dishes to the launching platform for the south face. This observatory, built in 1873 as a meteorological station,

It's 9:30 a.m. when the lift operator starts the cable car, and then we're hanging in the sky, moving up so fast that our ears pop before we have a chance to swallow. We rise above windblown snowfields, past rock outcrops, and finally into the clouds before the surreal telescope domes of Pic du Midi's observatory appear. They cover the entire mountaintop, the metal glistening in the sun.

Fog in the French Pyrenees has kept me waiting five days to ski the steeps of 9,439-foot Pic du Midi. I've begun to doubt that the mountain even exists—until its intimidating flanks come into view.

That I'm here at all is surprising, because the Pic has long been the exclusive territory of astronomers. Local guides lobbied town officials for years to open the mountain to skiers, using the astronomers' cable car for access, and finally in 2002 the Pic du Midi association of towns opened this icon of the Pyrenees to experts accompanied by an instructor or guide. The easiest—and most popular—runs are on the south face, above the Bareges and La Mongie resorts, which surround the base.

Near the summit, I look out over the impressive panorama of jagged peaks from the observatory's terrace. My guide, Stephane Delpech, remarks that the Pyrenees "do not get the proper respect like the Alps do, but wait till you ski them!" He smiles as he points to the 45-degree Poubelle ("Trash Can") couloir, barely wide enough to fit a pair of skis sideways. We climb past the fence behind the observatory and boot up a few more feet between domes and satellite dishes to the launching platform for the south face. This observatory, built in 1873 as a meteorological station, now hosts world-renowned astronomers, and its museum is worth a visit for a quick immersion in planets, galaxies, and coronas.

Our first few turns down the 40-degree slope are in perfect powder, but too soon we hit cement. "Oo-la-la," Delpech shouts, "la croute des Pyrenees"—a crust resulting from spring fog. We ski 4,600 vertical feet through rocks, crunchy snowfields, and tight gullies. My thighs burn as we finally traverse out at the bottom to a chairlift at Bareges.

On good days, fanatics can take four runs, skiing 18,400 vertical feet a day. But for most, it's more enjoyable to take one run and then retreat to Pyrenees culture in the valleys, which is what I do.

Back in the village of Bagneres-de-Bigorre, where medieval houses line the cobblestone streets, we finish a delicious meal of herbed lamb with a local cabernet before hitting the thermal baths of Aquensis, a remodeled 19th-century casino with a cathedral ceiling. As my quads start to relax in the warm water, I watch the clouds part once again, exposing Pic du Midi, rising dramatically away from its neighbors. I'm happy to have skied it, but equally glad to be right where I am.