Mackay ) is a town in Custer County, Idaho, United States. The population was 439 at the 2020 census. The town is pronounced "Mackie" with the accent on the first syllable. Highways - US 93 - to Challis (north) and Arco (south) Etymology The town was named in honour of John William Mackay who owned the local copper mines. The nearby Mackay Peak in the White Knob Mountains is also named after him. Geography Mackay is located at (43.911880, -113.613669), at an elevation of 5,905 feet (1,800 m). According to the United States Census Bureau, the city has a total area of , all of it land. About north of Mackay is Idaho's highest mountain: Borah Peak, with a summit elevation of . Mt. McCaleb, , overlooks the city. Climate The climate of Mackay ranges from lows of -40 °F (-40 °C) to highs of +30 °F (-1 °C) in the winter. In the summer, temperatures range from lows of 30 °F (-1 °C) to highs of 100 °F (38 °C) in some areas. Mackay has a fairly dry climate, typical of high desert bordering alpine areas. Sports The main athletic attraction in the city is Mackay High School. The Miners have won ten state championships in football in the 1A (previously A-4) division and five state championships in basketball. Volleyball, girls' basketball and track are other athletic opportunities in Mackay. Demographics 2010 census As of the census of 2010, there were 517 people, 247 households, and 137 families residing in the city. The population density was . There were 352 housing units at an average density of . The racial makeup of the city was 98.8% White, 0.2% African American, 0.6% Native American, and 0.4% from two or more races. Hispanic or Latino of any race were 1.0% of the population. There were 247 households, of which 21.9% had children under the age of 18 living with them, 43.3% were married couples living together, 7.3% had a female householder with no husband present, 4.9% had a male householder with no wife present, and 44.5% were non-families. 39.7% of all households were made up of individuals, and 23.9% had someone living alone who was 65 years of age or older. The average household size was 2.09 and the average family size was 2.72. The median age in the city was 47.5 years. 21.5% of residents were under the age of