Rio, Louisiana
Rio is an unincorporated community and census-designated place (CDP) in Washington Parish, Louisiana, United States.tates. It was first listed as a CDP in the 2020 census with a population of 137. Rio is located at the junction of Louisiana highways 1074 and 1075, south-southwest of Bogalusa. Demographics. 2020 census. "Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos can be of any race."