According to the United States Census Bureau, the city has a total area of , of which, is land and is water. The former community of Kinneyville is now a neighborhood fully contained within Prosser. The city has the ZIP code 99350.
according to the united states census bureau the city has a total area of  of which is land and is water the former community of kinneyville is now a neighborhood fully contained within prosser the city has the zip code 99350