Sunnyside is a city in Yakima County, Washington, United States. The population was 16,375 at the 2020 census, making it the second-most populous city in Yakima County.
Two specimens were collected in May 2020, one from Langley, British Columbia, about 13 kilometres (8 miles) north of Blaine, and one from Custer, Washington, 14 km (9 mi) southeast of Blaine.