Naselle is a census-designated place in Pacific County, Washington, United States located about 23 miles from the mouth of the Columbia River. The population was 421 at the 2020 census. The valley's Naselle River flows west into nearby Willapa Bay and then into the Pacific Ocean. Close about the town lie the evergreen-covered Willapa Hills. The riv…Naselle is a census-designated place in Pacific County, Washington, United States located about 23 miles from the mouth of the Columbia River. The population was 421 at the 2020 census. The valley's Naselle River flows west into nearby Willapa Bay and then into the Pacific Ocean. Close about the town lie the evergreen-covered Willapa Hills. The river's name has been spelled Nasel and Nasal. An early settler along the river called it the Kenebec. The name comes from the Nisal Indians, a Chinookan tribe formerly residing on the river.