Wrangell-St Elias National Park and Preserve encompasses 5.3 million hectares (13.2 million acres) in southcentral Alaska. The park extends to the Canadian border on the east and to the northern Gulf of Alaska on the south.
The park spans three climatic zones (coastal, transitional, and continental) and includes four major mountain ranges (the Wrangell Mountains, Chugach Mountains, St Elias Mountains, and the Alaska Range). Large expanses of open, low-elevation terrain occur within the Copper River basin, a relic of the huge proglacial Lake Atna (a lake formed at the foot of a glcier where it has retreated), which formed behind an ice dam at the confluence of the Copper and Chitina Rivers during the Pleistocene. The valley floor is now covered with braided river channels and surficial deposits mixed from alluvium and glacial outwash. Most of the rivers and streams are heavily influenced by glacier activity.