NASA satellite image, Wrangell-St. Elias National Park & Preserve, 2015.

Captured on May 28, 2013, this NASA satellite image of the Copper River Delta shows the amazing amount of sediment in the Gulf of Alaska. The Copper River and its tributaries drain 25,600 square miles of land and may have daily sediment loads of up to 750,000 cubic feet of earth. Where the river meets the ocean there is a layer of sediment being deposited at least 600 feet deep, creating the Copper River Delta. This sediment provides iron and nutrients for phytoplankton and marine plants, which in turn are food for animals higher on the food chain.