Some scholars have suggested the Chumash population may have declined substantially during a "protohistoric" period (1542–1769), when intermittent contacts with the crews of Spanish ships, including those of Juan Rodriguez Cabrillo's expedition, who wintered in the Santa Barbara Channel in AD 1542–43, brought disease and death. The Chumash appear to have been thriving in the late 18th century, when Spaniards first began actively colonizing the California coast. Whether the deaths began earlier with the contacts with ships' crews or later with the construction of several Spanish missions at Ventura, Santa Barbara, Lompoc, Santa Ynez, and San Luis Obispo, the Chumash were eventually devastated by the California Genocide carried out when the United States took over the territory. By 1900, their numbers had declined to just 200, while current estimates of Chumash people today range from 2,000 to 5,000.