Since 1977, King County has conducted an ongoing survey of historic resources. The resulting inventory provides a comprehensive list of the types of historic sites that exist throughout the county, including in a number of cities within the county.  The inventory provides basic information on the history of each site and why it might be important to the county’s heritage.  Currently the inventory includes more than 3500 properties. The County occasionally adds properties to the inventory as they’re brought to our attention, and as more modern buildings become old enough to be considered historic.