Cook Inlet (Tanaina: Tikahtnu; Sugpiaq: Cungaaciq) stretches 180 miles (290 km) from the Gulf of Alaska to Anchorage in south-central Alaska.
Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage. On its southern end, it merges with Shelikof Strait, Stevenson Entrance, Kennedy Entrance and Chugach Passage.
The Cook Inlet and both its arms are bodies of brackish water, containing a turbid mix of ocean salt-water and freshwater runoff from the various rivers and streams. The narrow channel of the inlet funnels the tides creating very fast-moving currents, rip tides, and occasional bore tides. Cook Inlet watershed is the most populated watershed in Alaska. The watershed covers about 100,000 km2 (39,000 sq mi) of southern Alaska, east of the Aleutian Range, south and east of the Alaska Range, receiving water from its tributaries, which include the Knik River, the Little Susitna River, the Susitna and Matanuska rivers, Eagle River, Ship Creek, Resurrection Creek, Portage Creek, Kenai River, and many others.
