The Chinook salmon, Oncorhynchus tshawytscha, (derived from Russian чавыча), is a species of anadromous fish in the salmon family. It is a Pacific Ocean salmon and is variously known as the king salmon, tyee salmon, Columbia River salmon, black salmon, chub salmon, hook bill salmon, winter salmon, Spring Salmon, Quinnat Salmon, and the blackmouth. Chinook Salmon are typically divided into "races" with "spring chinook", "summer chinook", and "fall chinook" being most common. Races are determined by the timing of adult entry into fresh water. A "winter chinook" run is recognized in the Sacramento River. Chinook salmon are highly valued, due in part to their scarcity relative to other Pacific salmon along most of the Pacific coast. Described and enthusiastically eaten by the Lewis and Clark Expedition, the Chinook salmon is spiritually and culturally prized among certain Native American tribes. Many celebrate the first spring Chinook caught each year with "First Salmon Ceremonies". While salmon fishing is still important economically for many tribal communities, the Chinook harvest is typically the most valuable. In Oregon, the fish were often traded at The Dalles between those tribes on the river and interior tribes who lacked access to the food source. Celilo Falls on the Columbia River were a traditional fishing grounds for Native Americans until Bonneville Dam inundated the falls. Dams on the Columbia and other rivers have been partly responsible for steep declines in salmon runs. The Chinook is the official state fish of Oregon.