Weiser ( WEE-zər) is a city in the rural western part of the U.S. state of Idaho and the county seat of Washington County. With its mild climate, the city supports farm, orchard, and livestock endeavors in the vicinity. The city sits at the confluence of the Weiser River with the great Snake River, which marks the border with Oregon. The population was 5,507 at the 2010 census.
The city was named after the nearby Weiser River, but exactly who that was named for is not precisely known. In one version it is for Peter M. Weiser, a soldier and member of the Lewis and Clark Expedition of 1804–1806. Another has it for Jacob Weiser, a trapper-turned-miner who struck it rich in Baboon Gulch in the Florence Basin of Idaho in 1861.
William Logan and his wife Nancy were the first white settlers in the vicinity of Weiser in 1863 building a roadhouse in anticipation of the opening of Olds Ferry west of them on the Snake River across from Farewell Bend. In 1863, Reuben Olds acquired a franchise from the Territorial Legislature and began operating Olds Ferry. Olds ferry business did well (as did Logan's) as it diverted much of the traffic from the old Snake River crossing point at Old Fort Boise. Increasing settlement on the Weiser River valley increased Weiser's population.