County
| FIPS code [3] | County seat [4] | Est. [4] | Origin [5] | Etymology [5] | Population [6] | Area [4] | Map |
|---|
| BakerCounty | 001 | Baker City | 1862 | Eastern portion of Wasco County | Named in honor of Edward Dickinson Baker (1811-1861), a senator from Oregon who was killed at Ball's Bluff, a battle of the American Civil War. | 16,912 | 3,068 sq mi
(7,946 km2) |  |
|---|
| BentonCounty | 003 | Corvallis | 1847 | Polk County | Named in honor of Thomas Hart Benton (1782–1858), a U.S. senator who advocated U.S. control over the Oregon Country. | 97,713 | 676 sq mi
(1,751 km2) |  |
|---|
| ClackamasCounty | 005 | Oregon City | 1843 | One of the original four districts of the Oregon Country | Named in honor of the Clackamas Indians, a Native American tribe living in the area. | 423,173 | 1,868 sq mi
(4,838 km2) |  |
|---|
| ClatsopCounty | 007 | Astoria | 1844 | Northern and western portions of the original Twality District | Named in honor of the Clatsop tribe of Native Americans, who lived along the coast of the Pacific Ocean prior to European settlement. | 41,102 | 827 sq mi
(2,142 km2) |  |
|---|
| ColumbiaCounty | 009 | Saint Helens | 1854 | Northern half of Washington County | Named for the Columbia River, which forms the county's northern borders. | 53,880 | 657 sq mi
(1,702 km2) |  |
|---|
| CoosCounty | 011 | Coquille | 1853 | Western parts of Umpqua and Jackson Counties | Named in honor of the Coos Tribe of Native Americans who lived in the region. | 64,212 | 1,600 sq mi
(4,144 km2) |  |
|---|
| CrookCounty | 013 | Prineville | 1882 | Southern part of Wasco County | Named in honor of George Crook (1828–1890), a U.S. Army officer who served in the American Civil War and the Indian Wars. | 26,952 | 2,980 sq mi
(7,718 km2) |  |
|---|
| CurryCounty | 015 | Gold Beach | 1855 | Coos County | Named in honor of George Law Curry (1820–1878), a governor of the Oregon Territory. | 23,296 | 1,627 sq mi
(4,214 km2) |  |
|---|
| DeschutesCounty | 017 | Bend | 1916 | Southern part of Crook County | Named for the Deschutes River, derived from "Riviere des Chutes", French for "River of the Falls". | 208,513 | 3,018 sq mi
(7,817 km2) |  |
|---|
| DouglasCounty | 019 | Roseburg | 1852 | Portion of Umpqua County which lay east of the Coast Range summit | Named in honor of Stephen A. Douglas (1813–1861), a U.S. Senator who supported Oregon statehood. | 112,435 | 5,037 sq mi
(13,046 km2) |  |
|---|
| GilliamCounty | 021 | Condon | 1885 | Eastern third of Wasco County | Named in honor of Cornelius Gilliam (1798–1848), a pioneer who commanded the forces of the Provisional Government of Oregon after the Whitman massacre. | 2,026 | 1,204 sq mi
(3,118 km2) |  |
|---|
| GrantCounty | 023 | Canyon City | 1864 | Parts of old Wasco and old Umatilla counties | Named in honor of Ulysses S. Grant (1822–1885), army officer who served in the Oregon Territory; a Union general in the American Civil War at the time of the county's creation; and subsequently President of the United States (1869–1877). | 7,215 | 4,529 sq mi
(11,730 km2) |  |
|---|
| HarneyCounty | 025 | Burns | 1889 | Southern two-thirds of Grant County | Named in honor of William S. Harney (1800–1889), a cavalry officer of the period, who was involved in the Pig War. | 7,440 | 10,135 sq mi
(26,250 km2) |  |
|---|
| Hood RiverCounty | 027 | Hood River | 1908 | Northwest portion of Wasco County | Named for the Hood River (a tributary of the Columbia River), which flows through the county. | 23,745 | 522 sq mi
(1,352 km2) |  |
|---|
| JacksonCounty | 029 | Medford | 1852 | Southwestern portion of Lane County and unorganized area south of Douglas and Umpqua Counties. | Named in honor of Andrew Jackson (1767-1845), the seventh President of the United States. | 220,768 | 2,785 sq mi
(7,213 km2) |  |
|---|
| JeffersonCounty | 031 | Madras | 1914 | Crook County | Named for Mount Jefferson, located on its western boundary, which was named for Thomas Jefferson. | 25,454 | 1,781 sq mi
(4,613 km2) |  |
|---|
| JosephineCounty | 033 | Grants Pass | 1856 | Western half of Jackson County | Named in honor of Virginia "Josephine" Rollins (1834–1912), the first white woman to make this county her home. | 87,821 | 1,640 sq mi
(4,248 km2) |  |
|---|
| KlamathCounty | 035 | Klamath Falls | 1882 | Western part of Lake County | Named in honor of the Klamath or Clamitte tribe, which has had a presence in the area for 10,000 years. | 70,003 | 5,945 sq mi
(15,397 km2) |  |
|---|
| LakeCounty | 037 | Lakeview | 1874 | Jackson and Wasco Counties | Named for numerous lakes and hot springs. | 8,293 | 7,940 sq mi
(20,565 km2) |  |
|---|
| LaneCounty | 039 | Eugene | 1851 | Southern part of Linn County and the portion of Benton County east of Umpqua County | Named in honor of Gen. Joseph Lane (1801–1881), the first governor of Oregon Territory. | 381,181 | 4,554 sq mi
(11,795 km2) |  |
|---|
| LincolnCounty | 041 | Newport | 1893 | Western portion of Benton County and Polk County | Named in honor of Abraham Lincoln (1809-1865), the sixteenth President of the United States. | 50,821 | 980 sq mi
(2,538 km2) |  |
|---|
| LinnCounty | 043 | Albany | 1847 | Southern portion of Champoeg (later Marion) County | Named in honor of U.S. Senator Lewis F. Linn (1795–1843) of Missouri, author of the Donation Land Act, which provided free land to settlers in the West. | 131,496 | 2,291 sq mi
(5,934 km2) |  |
|---|
| MalheurCounty | 045 | Vale | 1887 | Southern portion of Baker County | Named for the Malheur River (formally "Riviere au Malheur" or "Unfortunate River"), named by French trappers whose property and furs were stolen from their river encampment. | 32,044 | 9,888 sq mi
(25,610 km2) |  |
|---|
| MarionCounty | 047 | Salem | 1843 | One of the original four districts of the Oregon territory | Named in honor of Francis Marion (1732-1795), a Revolutionary War general of the Continental Army from South Carolina. | 346,741 | 1,185 sq mi
(3,069 km2) |  |
|---|
| MorrowCounty | 049 | Heppner | 1885 | Western portion of Umatilla County and a small portion of eastern Wasco County | Named in honor of Jackson L. Morrow (1827-1899), a state representative who advocated for the formation of the county. | 12,302 | 2,033 sq mi
(5,265 km2) |  |
|---|
| MultnomahCounty | 051 | Portland | 1854 | Eastern part of Washington and the northern part of Clackamas counties | Named for the Native American village of Multnomah, on Sauvie Island. The word is derived from nematlnomaq, probably meaning downriver. Lewis and Clark made note of the name in 1805, and applied that name to all local Indians. | 789,698 | 435 sq mi
(1,127 km2) |  |
|---|
| PolkCounty | 053 | Dallas | 1845 | Yamhill District | Named in honor of James Knox Polk (1795–1849), President of the United States at the time of the county's creation | 89,805 | 741 sq mi
(1,919 km2) |  |
|---|
| ShermanCounty | 055 | Moro | 1889 | Northeast corner of Wasco County | Named in honor of William Tecumseh Sherman (1820–1891), American Civil War general, and businessman, educator, and author | 1,951 | 823 sq mi
(2,132 km2) |  |
|---|
| TillamookCounty | 057 | Tillamook | 1853 | Clatsop, Yamhill and Polk Counties | Named in honor of the Tillamook (or Killamook) Native American people. | 27,417 | 1,102 sq mi
(2,854 km2) |  |
|---|
| UmatillaCounty | 059 | Pendleton | 1862 | Central portion of Wasco County | Named for the Umatilla River, derived from the Sahaptin word, possibly meaning laughing waters. | 80,053 | 3,215 sq mi
(8,327 km2) |  |
|---|
| UnionCounty | 061 | La Grande | 1864 | Baker County | Named for the town of Union, which had been established two years before and named by its founders for the "Union" of the states during the Civil War. | 25,944 | 2,037 sq mi
(5,276 km2) |  |
|---|
| WallowaCounty | 063 | Enterprise | 1887 | Eastern portion of Union County. | Named for the Nez Perce word wallowa to designate a tripod of poles used to support fish nets. The area was claimed by the Chief Joseph band of the Nez Perce as its hunting and fishing grounds. | 7,674 | 3,145 sq mi
(8,146 km2) |  |
|---|
| WascoCounty | 065 | The Dalles | 1854 | Parts of Clackamas, Lane, Linn and Marion counties | Named in honor of the Wasco (or Wascopam) Native American tribe. | 26,333 | 2,381 sq mi
(6,167 km2) |  |
|---|
| WashingtonCounty | 067 | Hillsboro | 1843 | One of the original four districts of the Oregon Country (as Twality District) | Named in honor of George Washington (1732-1799), the first President of the United States. | 598,865 | 724 sq mi
(1,875 km2) |  |
|---|
| WheelerCounty | 069 | Fossil | 1899 | Grant County, Gilliam County, and Crook County | Named in honor of Henry H. Wheeler (1826-1915), who operated the first mail stage line from The Dalles to Canyon City. | 1,436 | 1,715 sq mi
(4,442 km2) |  |
|---|
| YamhillCounty | 071 | McMinnville | 1843 | One of the original four districts of the Oregon Country | Named in honor of the Yamhelas, members of the Kalapuya Native American family, who lived along the Yamhill River in the western Willamette Valley. | 108,644 | 716 sq mi
(1,854 km2) |  |
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