Jefferson County


irrigation waters
An irrigation canal on Columbia Drive. (Oregon State Archives Scenic Image 20130926-D8C_5184​​)
County Seat: 66 SE D St., Madras 97741
Phone: 541-475-4451 (General); 541-475-3317 (Court Administrator)
Fax: 541-325-5018


Established: Dec. 12, 1914
Elev. at Madras: 2,242'
Area: 1,791 sq. mi.
Average Temp.: January 37.4° July 70.1°
Assessed Value: $2,066,146,569
Real Market Value: $4,442,739,974
(includes the value of non-taxed properties)
Annual Precipitation: 10.2"
Economy: Agriculture, forest products and recreation

Related Resources

"County QuickFacts" (population and economic data from U.S. Census Bureau)
County Seat Map (from Google Maps)
County Map (from ODOT) 

Incorporated Cities

Points of Interest

Mount Jefferson, Warm Springs Indian Reservation, Metolius River, Black Butte, Suttle Lake, Blue Lake, Santiam Summit, Lake Billy Chinook behind Round Butte Dam, Haystack Reservoir, Priday Agate Beds

History and General Information 

​​Jefferson County was established in 1914 from a portion of Crook County. It was named for Mount Jefferson on its western boundary. The county owes much of its agricultural prosperity to the railroad, which arrived in 1911 and to the development of irrigation projects in the late 1930s. The railroad, which links Madras with the Columbia River, was completed after constant feuds and battles between two lines working on opposite sides of the Deschutes River.

Vegetable, grass and flower seeds, garlic, mint and sugar beets are cultivated on some 60,000 irrigated acres. Jefferson County also has vast acres of rangelands and an industrial base related to forest products. With 300 days of sunshine and a low yearly rainfall, fishing, hunting, camping, boating, water-skiing and rock hunting are popular recreations.

County Officials

Commissioners—Chair Kelly Simmelink 2027; Wayne Fording 2025, Mark Wunsch 2027; Dist. Atty. Steven Leriche 2025; Assess. Jean McCloskey 2025; Clerk Kate Zemke 2023; Sheriff Jason Pollock 2027; Treas. Brandie McNamee 2025; Surv. Gary L. DeJarnatt