GAP, France – Floyd Landis knows the Alps well – he sweated up enough steep mountain climbs to help teammate Lance Armstrong clinch three of his seven Tour de France wins.

Tuesday, however, Landis will be doing it for himself.

“I always believed I could do it from the beginning,” said Landis, who trails overall race leader Oscar Pereiro by 1 minute, 29 seconds. “I’ve proved I’m strong enough to win the Tour.”

By the end of Tuesday’s 15th stage, which winds through 21 sharp bends to finish at the summit of the famed L’Alpe d’Huez, the Phonak team leader will have a clearer idea if he has what it takes.

But then come two more grueling mountain stages in the Alps as one of the most unpredictable Tours in years enters its final week.

“My objective is to get to (Saturday’s) time trial without losing too much time,” Landis said Monday during a rest day in Gap. “I’m very confident in my time-trialing ability.”

He argues it’s still too early to worry about the yellow jersey, which he wore two days last week.

“I have to stay focused on the big picture, rather than think of living the moment,” he said. “That wouldn’t be wise.”

With Armstrong retired and favorites such as Jan Ullrich and Ivan Basso out on suspicion of doping, a number of riders are contending for the coveted yellow jersey.

Landis, who sits 8 seconds ahead of Cyril Dessel of France, is confident Pereiro will wilt in the Alps and considers Denis Menchov his main rival.

“Menchov is the guy I have to follow the most,” said Landis of the Rabobank rider, who’s 61 seconds behind in fourth place.

Tuesday’s stage features a mammoth climb – Col d’Izoard, a nine-mile ascent at a 7-percent gradient. It’s known as “hors categorie,” or beyond classification, because it is so difficult.

Tour riders last took on the Col d’Izoard in 2003, when Aitor Garmendia of Spain was first over the top, and Alexandre Vinokourov of Kazakhstan won the stage, which ended in Gap.

Riders face six more punishing climbs on Wednesday and Thursday.