Washington, USAi

Regional Level Types
Washington	State
USA	Country

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Washington is the north-westernmost state of the contiguous United States, bordered by Canada (British Columbia) to the north, Idaho to the east, Oregon to the south, and the Pacific Ocean to the west. It covers about 184,827 km² and is divided physiographically by the Cascade Range, which strongly controls climate, drainage, and landscape. The Willamette Meridian governs all public-land surveys in the state.

Physically, Washington is one of the most diverse states in North America. Western Washington is characterised by rugged coastlines, the deeply indented Puget Sound, and the heavily forested Olympic Mountains, which include temperate rainforests and receive very high rainfall. Eastern Washington, lying in the rain shadow of the Cascades, consists mainly of semi-arid plateaux, loess hills, and broad river valleys of the Columbia Basin. The state’s highest point is Mount Rainier (4,392 m), an active stratovolcano and the most glaciated peak in the contiguous USA. Quaternary glaciation has profoundly shaped much of the terrain, particularly around Puget Sound and in alpine areas.

Geologically, Washington lies along an active convergent plate margin, where the Juan de Fuca Plate is subducting beneath the North American Plate. This process drives frequent seismicity and fuels the Cascade Volcanic Arc, which includes Mount Rainier, Mount St. Helens, Mount Baker, Glacier Peak, and Mount Adams. Much of eastern Washington is underlain by the Miocene Columbia River Basalt Group, one of the largest continental flood-basalt provinces on Earth, while western Washington consists of a complex assemblage of accreted terranes made up of oceanic crust, island-arc rocks, and sedimentary sequences sutured to the continent during the Mesozoic and Cenozoic.

Washington has a moderate but geologically varied mineral and mining heritage. Historically, the state produced gold, silver, copper, lead, and zinc, with important districts in the Okanogan Highlands, North Cascades, and Colville region, as well as widespread placer gold in river systems. Coal was mined extensively in the Puget Sound area during the 19th and early 20th centuries. Today, extraction is dominated by industrial minerals such as sand, gravel, limestone, and basalt for construction, while mineralogical interest remains high due to well-developed hydrothermal systems and alpine environments that yield diverse and often well-formed mineral specimens.

Commodity List

This is a list of exploitable or exploited mineral commodities recorded from this region.

Mineral List

Mineral list contains entries from the region specified including sub-localities

469 valid minerals. 9 (TL) - type locality of valid minerals. 2 (FRL) - first recorded locality of unapproved mineral/variety/etc. 3 erroneous literature entries.

Rock Types Recorded

Rock list contains entries from the region specified including sub-localities