Assessment is necessary to calculate the equitable amount of property tax from each parcel to pay for governmental services such as, schools, counties, cities, The median property tax in Douglas County, Oregon is $1,245 per year for a home worth the median value of $185,100. Douglas County collects, on average, 0.67% of a property's assessed fair market value as property tax. Welcome to the Douglas County Assessor’s Web site. The purpose of this site is to provide convenient access to information 24 hours a day, 7 days a week. On this site, or linked from this site, you will find information regarding the property assessment process, assessment history in Oregon, statutes that control the process, calendar of assessment/tax events in Oregon, information on how to