King County Dept. of Natural Resources and Parks, Water and Lands Resources Division (2016). Wellhead Protection Areas - Six Month Time of Travel / kcwhpa 6mo area [Washington (State)--King County]. . https://gis-kingcounty.opendata.arcgis.com/datasets/kingcounty::wellhead-protection-areas-six-month-time-of-travel-kcwhpa-6mo-area (web service)