Adventures in Living.
Established February 18, 1913 with its county seat at Rigby. Named for Thomas Jefferson, third president of the United States. The first settlers were Mormons who constructed irrigation systems.
Jefferson County Web Site
County Seat: Rigby
Land Area: 1,106 square miles
Rigby, ID 83442-0538
Phone: (208) 745-7756 Fax: (208) 745-6636
Idaho Territorial Sesquicentennial