Hermiston is a city in Umatilla County, Oregon, United States. Its population of 20,322 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 92,261 at the 2020 census. Hermiston sits near the junction of I-82 and I-84, and is 7 miles (11 km) south of the Columbia River, the Washington state line, Lake Wallula, and the McNary Dam. The Hermiston area has become a hub for logistics and data center activity due to the proximity of the I-82 and I-84 interchange, Pacific Northwest fiber-optic backbone, and low power costs.