The Interior region is the largest region of the state encompasses 78% (443,153 mi2 or 1,147,760 km2) of Alaska’s 570,376 square miles (1,477,267 km2), and includes the state’s largest river systems (Yukon, Kuskokwim, Colville, and Noatak rivers). The area encompassed is the size of the next two largest U. S. states, Texas and California, combined.
The Interior region includes 33,904 miles (54,563 km) of coastline: 20% of Alaska’s total. Countless lakes dot the landscape. In the flat lowlands, it is often difficult to determine where one lake ends and another begins. Lakes freeze and remain frozen throughout the winter season. Ice fishing is a popular pastime.
The state’s largest river systems and its ten longest rivers are located in the Interior region. These rivers wind their way over Arctic tundra and through boreal forest. They roar through canyons and meander across flats. They range in turbidity from the crystal water of spring-fed systems to the blue/gray silt-laden waters of glacial runoff. Side sloughs are the color of tea, stained by tannins. Many young rivers run murky as they cut their way through the earth in search of bedrock. Most rivers freeze during winter, although open leads can develop at any time. Ice fishing, including set lining for burbot, keeps anglers occupied during the winter months.