Thomas Mountain (1822-1915) was a member of the U.S. Exploring Expedition, 1838-1842, a river captain, and and employee of the Oregon Railway and Navigation Company. Collection consists of deeds for land in Couch's Addition, Portland, Oregon, deed for cemetery plot in Multnomah County, Oregon, and receipts and correspondence, 1873-1899, of Thomas Mountain; land claims and other legal documents in Washington Territory, 1853-1865, of Raphael Brunn.