Wrangell - St Elias National Park & Preserve - Watersheds

Some estimates suggest that 62% of all of Alaska is wetlands and the same percentage probably is true for Wrangell-St. Elias. Four large major river watersheds occur within the park, the Copper, Chitina, White, and Tanana rivers, dividing the landscape with major salmon fisheries in the summer overlaid by access routes across the frozen surfaces in the winter.

Large expanses of open, low elevation terrain occurs within the Copper River basin, a relic of the huge pro-glacial Lake Ahtna which formed behind an ice dam at the confluence of the Copper and Chitina Rivers during the Pleistocene Epoch. 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 in the park are heavily influenced by glacier activity. Glacial abduction and global industrialization are changing the character of the Copper River basin and of the watersheds within Wrangell-St. Elias. The extent of how those changes may affect the ecosystem are yet to be determined.