Indian Sweat Bath near Wishram, c.1930 Marshall Family Collection CN 015455

Until the close of the eighteenth century, the Columbia River country existed in relative isolation from the disease pools—smallpox, measles, whooping cough, typhoid, malaria, and cholera—that had proved so deadly to people who lacked immunities to Old World contagions. While the Rocky Mountains and ocean barriers limited travel and access to the region for some time, that isolation began to erode in the late-eighteenth century when Russian, Spanish, British, and American ships increasingly touched shore along the Northwest Coast. The best documented of the major epidemics—and a major cause of Native population decline—was a series of seasonally recurring malaria outbreaks on the lower Columbia River between 1830 and 1833. Coming first from West Africa to Central America, the initial outbreak in the Oregon Country took place around Fort Vancouver in August 1830. Spread by an insect vector—in this case, mosquitoes—malaria returned annually to ravage Indian and white populations alike, but the malarial infections affected the two peoples in dramatically different ways. While whites developed fever and sickness, malaria was lethal to Native people.

The reoccurring malaria epidemics were devastating to Indians along the lower Columbia River, in the Willamette Valley, and in villages on Oregon’s coastal estuaries. In a letter to Hudson’s Bay Company officials in October 1830, Chief Factor John McLoughlin estimated the Native death toll at 75 percent in the vicinity of Fort Vancouver. Visiting botanist David Douglas left a similar description that same month: “A dreadfully fatal intermittent fever broke out in the lower parts of this river about eleven weeks ago, which has depopulated the country.” By the time the epidemic had run its course, about 90 percent of the approximately 14,000 people who lived on the lower Columbia and in the Willamette Valley had died. When Lieutenant Charles Wilkes of the United States Exploring Expedition visited the region in 1841, he counted 575 Chinook survivors on the Columbia and 600 Kalapuyans in the Willamette Valley.

The well-documented malaria epidemic was only one of several exogenous diseases that struck down Native people. The ever-increasing traffic on the Oregon Trail brought new contagions, especially those associated with childhood, such as chicken pox, measles, and whooping cough. These pathogens struck disproportionately against children, thus skewing the average age of Indian communities. By the close of the American Civil War, disease alone had reduced the Native population by about 80 percent, a catastrophic decrease that parallels similar declines elsewhere in the Americas. Anthropologist Eugene Hunn has pointed out that Indian-white relations in the Pacific Northwest “has been first and foremost a history of the ravages of disease which drastically reduced native populations.” The pathogens also weakened the abilities of Indian groups to resist the increasing numbers of Euro Americans who were entering the lower Columbia and Willamette valleys in the 1830s and 1840s.

© William G. Robbins, 2002

Themes: People and the Environment,Social Relations

Regions: Oregon Country

Date: 1800-1850

Author: William G. Robbins

Summary:
Until the close of the eighteenth century, the Columbia River country existed in relative isolation from the diseases that proved so deadly to people lacking genetic immunities to Old World contagions.