U.S. #1019 commemorates the 100th anniversary of the establishment of the Washington Territory. The stamp pictures early pioneers, the state flower – the rhododendron – and several products Washington is known for. Washington Territory The first American to reach Washington was Captain Robert Gray of the Boston Company. Gray headed a fur-trading expedition that sailed into the harbor that now bears his name. He reached the mouth of the Columbia River in 1792. Gray’s explorations became the source of American claims to the area. In 1805, the Lewis and Clark Expedition explored Washington by following the route of the Columbia River to the Pacific Ocean. The Lewis and Clark Expedition gave America another claim to the land of the northwest. By the early 1800s, fur traders from U.S. and Britain had settled in the region. In 1810, the Canadian North West Company established Spokane House near today’s Spokane. Fur trader John Jacob Astor established the first permanent American settlement with the founding of Fort Okanogan.