During the last quarter of the 18th century, the first Spanish settlements were established in what later became the Las Californias Province of the Viceroyalty of New Spain. Reacting to interest by the Russians and, later, the British in the fur-bearing animals of the Pacific north coast, Spain further extended the series of Catholic missions, accompanied by troops and establishing ranches, along the southern and central coast of California. These missions were intended to demonstrate the claim of the Spanish Empire to what is now California. By 1823, 21 Spanish missions had been established in Alta California. Operations were based out of the naval base at San Blas and included not only the establishment and supply of missions in California, but a series of exploration expeditions to the Pacific Northwest and Alaska.