Provisional and Territorial Records Guide
Island County History and Records
Island County was the last county created north of the Columbia River by Oregon's territorial government. Created in 1853, the county originally included all of northwestern Washington and was carved out of the original Thurston County. Island County contained present day San Juan, Skagit, Snohomish, and Whatcom Counties within its borders. Located within Puget Sound, Island County consists primarily of Whidbey Island, the second largest island in the continental United States, and Camano Island. Coveland served as the county seat until March 3, 1891, when it was replaced by Coupeville.
The same act which created Island County also established two election precincts, one at Snohomish, and the other at Whidbey Island. Another act, two weeks later, appointed county officers: three commissioners, a sheriff, and a probate clerk. In the last two months prior to the creation of Washington Territory, the territorial legislative assembly passed three laws which affected Island County government. These involved the collection and distribution of school funds, the levying of road taxes, and US District Court judge assignments. On March 2, 1853, Washington Territory was created and Island County was no longer under the jurisdiction of Oregon Territory.