Hermiston is a city in Umatilla County, Oregon, United States. Its population of 18,200 makes it the largest city in Eastern Oregon. Hermiston is the largest, and fastest-growing, city in the Hermiston-Pendleton Micropolitan Statistical Area, the eighth largest Core Based Statistical Area in Oregon with a combined population of 87,062 at the 2010 census. Hermiston sits near the junction of I-82 and I-84, and is 7 miles south of the Columbia River, Lake Wallula, and the McNary Dam. The Hermiston area has become a transportation and logistics hub due to the proximity of the I-82 and I-84 interchange, and central location between the major Pacific Northwest metropolitan areas. The city is also known for its watermelons, which are part of its branding.