At the outbreak of the war, regular U.S. Army troops in the District of Oregon were withdrawn from posts in Oregon and Washington Territory and sent east. Volunteer cavalry and infantry were recruited in California and sent north to Oregon to replace the Federal troops and keep the peace and protect the populace. Oregon also raised the 1st Oregon Cavalry that was activated in 1862 and served until June 1865. During the Civil War, immigrants to the newfound gold fields in Idaho and Oregon continued to clash with the Paiute, Shoshone and Bannock tribes of Oregon, Idaho and Nevada until relations degenerated into the bloody 1864 - 1868 Snake War. The 1st Oregon Volunteer Infantry Regiment was formed in 1864 and its last company was mustered out of service in July 1867. Both units were used to