Island County administrative offices are located at 1 NE Seventh Street, Coupeville, WA 98239; phone: 360-678-5111.
The county was created from Thurston County in 1852. It is named to reflect its composition consisting of 9 Puget Sound islands: Whidbey, Camano, Baby, Be Ure, Deception, Kalamut, Minor, Smith and Strawberry.
The county's size was reduced over time as San Juan, Skagit, Snohomish and Whatcom counties were created from its parts.
- Aurora County Courthouse
- Lincoln House
- Raesly House
- Sweep Hotel
- Smith, William P., House
- Hilton House
- Hofmeister House
- South Dakota Department of Transportation Bridge No. 02-007-220
- South Dakota Department of Transportation Bridge No. 02-012-240