COUNTY	2015 POPULATION	SQUARE MILES	COUNTY SEAT	BOARD SIZE	FOUNDED
Baker County	16,005	3,088	Baker City	3	1862
Benton County	87,572	679	Corvallis	3	1847
Clackamas County	401,515	1,883	Oregon City	5	1843
Clatsop County	37,831	1,084	Astoria	5	1844
Columbia County	49,600	688	Saint Helens	3	1854
Coos County	63,121	1,806	Coquille	3	1853
Crook County	21,630	2,987	Prineville	3	1882
Curry County	22,483	1,988	Gold Beach	3	1855
Deschutes County	175,268	3,055	Bend	3	1916
Douglas County	107,685	5,134	Roseburg	3	1852
Gilliam County	1,859	1,223	Condon	3	1885
Grant County	7,185	4,529	Canyon City	3	1864
Harney County	7,200	10,226	Burns	3	1889
Hood River County	23,137	533	Hood River	5	1908
Jackson County	212,567	2,802	Medford	3	1852
Jefferson County	22,666	1,791	Madras	3	1914
Josephine County	84,745	1,642	Grants Pass	3	1856
Klamath County	66,016	6,136	Klamath Falls	3	1882
Lake County	7,829	8,358	Lakeview	3	1874
Lane County	362,895	4,722	Eugene	5	1851
Lincoln County	47,038	1,194	Newport	3	1893
Linn County	120,547	2,309	Albany	3	1847
Malheur County	30,380	9,930	Vale	3	1887
Marion County	330,700	1,193	Salem	3	1843
Morrow County	11,190	2,049	Heppner	3	1885
Multnomah County	790,294	466	Portland	5	1854
Polk County	79,391	744	Dallas	3	1845
Sherman County	1,680	831	Moro	3	1889
Tillamook County	25,653	1,333	Tillamook	3	1853
Umatilla County	76,531	3,231	Pendleton	3	1862
Union County	25,790	2,039	La Grande	3	1864
Wallowa County	6,856	3,152	Enterprise	3	1887
Wasco County	25,775	2,395	The Dalles	3	1854
Washington County	574,326	726	Hillsboro	5	1843
Wheeler County	1,358	1,715	Fossil	3	1899
Yamhill County	102,659	718	McMinnville	3	1843

* consolidated city-county government