Located in the Columbia River Gorge between Hood River and The Dalles, Mosier is both a town and an agricultural valley. The population of the town of Mosier is about 468 people, in 2020 with more than a thousand people in the valley.

Mosier's white settler history dates to 1854, when Jonah H. Mosier (1821-1894) built a series of sawmills at the mouth of Mosier Creek. His son, Jefferson N. Mosier (1860-1928), platted the town and, like his father, became active in local and state affairs. During the late nineteenth century, Mosier had a railroad station and was a steamboat landing for boats headed upriver.

In 1878, Amos Root established the Rosedale Fruit Farm, the first commercial orchard in the area. The Mosier Fruit Growers' Association, located in the center of town, was established in 1907. Since then, cherries have become the desired tree fruit in the valley, with many new varieties being marketed locally and internationally.

Mosier was incorporated in 1914. Long-established organizations include the Mosier Community School (a charter school), a post office, the Mosier Grange #234, the First Christian Church, the American Legion, and the 4-H. With the town’s population growing in recent years, there are plans for new housing developments.

The town has attracted tourists, many of whom visit the nearby Mosier Twin Tunnels, part of the Historic Columbia River Highway State Trail, which was opened to cyclists and hikers in 2000. The Tom McCall Nature Conservancy Preserve—home to more than 300 species of wildflowers—and the boat launch at the mouth of Rock Creek into the Columbia River also draw visitors to the area.