Downey, Idaho  Downey is a city in the Marsh Valley in southern Bannock County, Idaho, United States. It is part of the Pocatello Metropolitan Statistical Area. The population was 625 at the 2010 census. The community was reportedly named after one Mr. Downey, a director of the Union Pacific Railroad. However, researchers have been unable verify existence of said Mr. Downey. Notwithstanding, some have asserted he was a track worker, not a director. Downey is located at (42.429312, -112.122397), at in Marsh Valley. It lies on the route of U.S. Highway 91. According to the United States Census Bureau, the city has a total area of , all of it land. As of the census of 2010, there were 625 people, 255 households, and 168 families residing in the city. The population density was . There were 290 housing units at an average density of . The racial makeup of the city was 98.1% White, 0.2% Native American, 0.8% Pacific Islander, 0.5% from other races, and 0.5% from two or more races. Hispanic or Latino of any race were 1.6% of the population. There were 255 households, of which 27.1% had children under the age of 18 living with them, 55.3% were married couples living together, 5.1% had a female householder with no husband present, 5.5% had a male householder with no wife present, and 34.1% were non-families. 30.6% of all households were made up of individuals, and 19.6% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 3.13. The median age in the city was 47.1 years. 27.2% of residents were under the age of 18; 5% were between the ages of 18 and 24; 16.6% were from 25 to 44; 26.8% were from 45 to 64; and 24.6% were 65 years of age or older. The gender makeup of the city was 49.8% male and 50.2% female. As of the census of 2000, there were 613 people, 233 households, and 165 families residing in the city. The population density was 622.8 people per square mile (241.5/km2). There were 264 housing units at an average density of 268.2 per square mile (104.0/km2).