The Saint Elias Mountains (French: Chaîne Saint-Élie) are a subgroup of the Pacific Coast Ranges, located in southeastern Alaska in the United States, Southwestern Yukon and the very far northwestern part of British Columbia in Canada.
[6] The Yakutat plate is transported northwards along the active Fairweather Fault, which probably started more than 35 million years ago.
The up-to-12-kilometre (7.5 mi)-thick sediments that have been deposited on top of the Yakutat plate became imbricated and deformed as they were scraped off and compose today the southern (coastal) flanks of the St. Elias Mountains.
At the syntaxis region the tectonic style changes from strike-slip motion along the Fairweather Fault to collision west of Malaspina Strait.
This tectonic transition concentrates stress in the crust at the syntaxis that together with efficient glacial erosion results in positive feedback processes that through time forms extreme high mountain peaks and local relief, and rapid exhumation of rocks from up to 10 km (6.2 mi) depths to the surface.