The Cayuse War was an armed conflict that took place in the Northwestern United States from 1847 to 1855 between the Cayuse people of the region and the United States Government and local American settlers. Caused in part by the influx of disease and settlers to the region, the immediate start of the conflict occurred in 1847 when the Whitman massacre took place at the Whitman Mission near present-day Walla Walla, Washington when thirteen people were killed in and around the mission. Over the next few years the Provisional Government of Oregon and later the United States Army battled the Native Americans east of the Cascades. This was the first of several wars between the Native Americans and American settlers in that region that would lead to the negotiations between the United States and Native Americans of the Columbia Plateau, creating a number of Indian reservations. Causes In 1836, two missionaries—Marcus and Narcissa Whitman—founded the Whitman Mission among the Cayuse Native Americans at Waiilatpu, six miles west of present-day Walla Walla, Washington. In addition to evangelizing, the missionaries established schools and grist mills and introduced crop irrigation. While it started off fast, the Whitmans did not have any Cayuse baptized into their church. Due to lack of success and high costs, in 1842, the American Board of Commissioners for Foreign Missions was going to close the mission until Marcus Whitman returned east pleading to keep the mission open. Returning the following year, he joined approximately a thousand settlers traveling to Oregon Country. The sudden influx of American settlers led to an escalation of tension between natives and settlers, which owed much to cultural misunderstandings and mutual hostilities. For instance, the Cayuse believed that to plow the ground was to desecrate the spirit of the Earth. The settlers, as agriculturalists, naturally did not accept this. The Cayuse expected payment from wagon trains passing through their territory and eating the wild food on which the tribes depended; the settlers did not understand this and instead drove away the men sent to exact payment, in the belief that they were merely "beggars". The new settlers brought diseases with them. In 1847, an epidemic of measles killed half the Cayuse. The Cayuse suspected that Marcus Whitman—a practicing physician and religious leader, hence a shaman—was responsible for the deaths of their families, causing the disaster to make way for new immigrants. Seeking revenge, Cayuse tribesmen