Denio, Nevada is an unincorporated community that lies on the Nevada-Oregon state line in Humboldt County, Nevada and Harney County, Oregon, in the United States. The community is also known as Denio, Oregon. There was formerly a Denio, Oregon post office north of the state line. Most of the town lies south of the state line in Nevada. The southern part of the community includes a post office with ZIP code 89404, a community center, a library, and the Diamond Inn Bar, the center of the town's social life. The only services available in Denio are a few groceries available for sale at the bar. Denio Junction is about two miles (3 km) south of Denio, at the T-shaped junction of State Route 140 and State Route 292. Denio Junction's motel provides gasoline, food, groceries, and lodging. Recreational activities available in the Denio area include fishing, opal mining, rockhounding, hunting, and visiting the hot springs. Air transportation is available at the Denio Junction Airport. Humboldt County School District operates the Denio School, a kindergarten-eighth grade (K-8) school, on the Nevada side of the state line.