Spanish expeditions to the Pacific Northwest

During the Age of Discovery, the Spanish Empire undertook several expeditions to the Pacific Northwest of North America. Spanish claims to the region date to the papal bull of 1493, and the Treaty of Tordesillas signed in 1494. In 1513, this claim was reinforced by Spanish explorer Vasco Núñez de Balboa, the first European to sight the Pacific Ocean, when he claimed all lands adjoining this ocean for the Spanish Crown. Spain only started to colonize the claimed territory north of present-day Mexico in the 18th century, when it settled the northern coast of Las Californias.

Starting in the mid-18th century, Spain's claims in the Pacific Northwest began to be contested by the British and Russians, who established fur trading posts and other settlements in the region. King Charles III of Spain and his successors sent several expeditions from New Spain to present-day Canada and Alaska between 1774 and 1793 to strengthen the Spanish claims. These efforts would eventually come to naught when Spanish claims in the region were ceded to the American government in the 1819 Adams–Onís Treaty.