County FIPS code [3] County seat [4] Est. [4] Origin [5] Etymology [5] Population [6] Area [4] Map Baker 001 Baker City 1862 Eastern portion of Wasco County Named in honor of Edward Dickinson Baker , who died in combat while serving as Oregon senator. 16,912 3,068 sq mi7,946 km2 ) Benton 003 Corvallis 1847 Polk County Named for Thomas Hart Benton , senator and advocate of U.S. annexation of the Oregon Country . 97,713 676 sq mi1,751 km2 ) Clackamas 005 Oregon City 1843 One of the original four districts of the Oregon Country Named for the Clackamas people , a local Native American tribe. 423,173 1,868 sq mi4,838 km2 ) Clatsop 007 Astoria 1844 Northern and western portions of the original Twality District Named for the Clatsop , a local Native American tribe. 41,102 827 sq mi2,142 km2 ) Columbia 009 Saint Helens 1854 Northern half of Washington County Named for the neighboring Columbia River . 53,880 657 sq mi1,702 km2 ) Coos 011 Coquille 1853 Western parts of Umpqua and Jackson Counties Named for the Coos people , a regional Native American group. 64,212 1,600 sq mi4,144 km2 ) Crook 013 Prineville 1882 Southern part of Wasco County Named for George Crook , a Union army officer in the Civil War and Indian Wars . 26,952 2,980 sq mi7,718 km2 ) Curry 015 Gold Beach 1855 Coos County Named for George Law Curry , governor of the Oregon Territory . 23,296 1,627 sq mi4,214 km2 ) Deschutes 017 Bend 1916 Southern part of Crook County Named for the Deschutes River from French Riviere des Chutes ' River of the falls' 208,513 3,018 sq mi7,817 km2 ) Douglas 019 Roseburg 1852 Portion of Umpqua County which lay east of the Coast Range summit Named for senator Stephen A. Douglas , a supporter of Oregon's admission to the union. 112,435 5,037 sq mi13,046 km2 ) Gilliam 021 Condon 1885 Eastern third of Wasco County Named for Oregon pioneer Cornelius Gilliam (1798–1848). 2,026 1,204 sq mi3,118 km2 ) Grant 023 Canyon City 1864 Parts of old Wasco and old Umatilla counties Named for Ulysses S. Grant prior to his election as president, in recognition of his military service. 7,215 4,529 sq mi11,730 km2 ) Harney 025 Burns 1889 Southern two-thirds of Grant County Named in honor of cavalry officer William S. Harney . 7,440 10,135 sq mi26,250 km2 ) Hood River 027 Hood River 1908 Northwest portion of Wasco County Named for the Hood River . 23,745 522 sq mi1,352 km2 ) Jackson 029 Medford 1852 Southwestern portion of Lane County and unorganized area south of Douglas and Umpqua Counties. Named for President Andrew Jackson . 220,768 2,785 sq mi7,213 km2 ) Jefferson 031 Madras 1914 Crook County Named for the adjacent Mount Jefferson , itself named for President Thomas Jefferson . 25,454 1,781 sq mi4,613 km2 ) Josephine 033 Grants Pass 1856 Western half of Jackson County Named for Virginia "Josephine" Rollins, the first female settler in the area. 87,821 1,640 sq mi4,248 km2 ) Klamath 035 Klamath Falls 1882 Western part of Lake County Named for the Klamath people , a local Native American tribe. 70,003 5,945 sq mi15,397 km2 ) Lake 037 Lakeview 1874 Jackson and Wasco Counties Named for the large number of local lakes and springs. 8,293 7,940 sq mi20,565 km2 ) Lane 039 Eugene 1851 Southern part of Linn County and the portion of Benton County east of Umpqua County Named for Joseph Lane , the first governor of the Oregon Territory . 381,181 4,554 sq mi11,795 km2 ) Lincoln 041 Newport 1893 Western portion of Benton County and Polk County Named for President Abraham Lincoln . 50,821 980 sq mi2,538 km2 ) Linn 043 Albany 1847 Southern portion of Champoeg (later Marion) County Named for Lewis F. Linn , sponsor of the Donation Land Act . 131,496 2,291 sq mi5,934 km2 ) Malheur 045 Vale 1887 Southern portion of Baker County Named for the Malheur River , itself from French Riviere au Malheur ' Unfortunate River' 32,044 9,888 sq mi25,610 km2 ) Marion 047 Salem 1843 One of the original four districts of the Oregon territory Named for Francis Marion (1732-1795), a Revolutionary War general. 346,741 1,185 sq mi3,069 km2 ) Morrow 049 Heppner 1885 Western portion of Umatilla County and a small portion of eastern Wasco County Named for state representative Jackson L. Morrow , an advocate for the formation of the county. 12,302 2,033 sq mi5,265 km2 ) Multnomah 051 Portland 1854 Eastern part of Washington and the northern part of Clackamas counties Named for the Multnomah people , a Chinookan band from Sauvie Island . 789,698 435 sq mi1,127 km2 ) Polk 053 Dallas 1845 Yamhill District Named for President James Knox Polk , who was serving during the county's creation. 89,805 741 sq mi1,919 km2 ) Sherman 055 Moro 1889 Northeast corner of Wasco County Named for Union general William Tecumseh Sherman . 1,951 823 sq mi2,132 km2 ) Tillamook 057 Tillamook 1853 Clatsop, Yamhill and Polk Counties Named for the Tillamook people , a Native American tribe. 27,417 1,102 sq mi2,854 km2 ) Umatilla 059 Pendleton 1862 Central portion of Wasco County Named for the adjacent Umatilla River , derived from a Sahaptin , word possibly meaning laughing waters . 80,053 3,215 sq mi8,327 km2 ) Union 061 La Grande 1864 Baker County Named for the town of Union , itself named for the Union during the Civil War . 25,944 2,037 sq mi5,276 km2 ) Wallowa 063 Enterprise 1887 Eastern portion of Union County. Named after the Nez Perce wallowa , a tripod of poles used to support fish nets. 7,674 3,145 sq mi8,146 km2 ) Wasco 065 The Dalles 1854 Parts of Clackamas, Lane, Linn and Marion counties Named for the Wasco people , a Native American tribe. 26,333 2,381 sq mi6,167 km2 ) Washington 067 Hillsboro 1843 One of the original four districts of the Oregon Country (as Twality District) Named for president George Washington . 598,865 724 sq mi1,875 km2 ) Wheeler 069 Fossil 1899 Grant County, Gilliam County, and Crook County Named for Henry H. Wheeler, an early Oregon mail carrier. 1,436 1,715 sq mi4,442 km2 ) Yamhill 071 McMinnville 1843 One of the original four districts of the Oregon Country Named for the Yamhill band of Kalapuya , a local Native American group. 108,644 716 sq mi1,854 km2 ) 
