What is a State Soil?

A state soil is represented by a soil series that has special significance to a particular state. Each state in the United States has selected a state soil, fifteen of which have been legislatively established. These "Official State Soils" share the same level of distinction as official state flowers and birds.

Washington’s state soil is called Tokul. The name Tokul is derived from a small community and creek in King County, WA. The state of Washington has more than 1,000,000 acres of Tokul soils. These soils are on the western side of the Cascade Mountains along the Puget Trough, from south of Seattle north to the Canadian border. Washington was the first state to recognize soils that formed in volcanic ash (Andisols) as a state soil.

Tokul soils are among the most productive soils in the world. These soils support Douglas-fir and other conifer trees, which are the source of Washington’s nickname, the Evergreen State. The State of Washington has hundreds of soils that are influenced by volcanic ash. These volcanic soils are used for crop production, timber production, livestock grazing, recreation, and watershed. Most areas of Tokul soils are used for timber production, but some of the smaller areas are used as pasture and for urban development. Tokul soils are limited as sites for homes. Water perches above the dense glacial till during wet periods, which makes steep slopes unstable for structures.

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