thumb|upright=1.2|Farm and barren hills near Riverside
Riverside is a town in Okanogan County, Washington, United States. The population was 280 at the 2010 census, and increased to 329 at the 2020 census.
History
Riverside was first settled in the 1880s by Uriah Ward. When steamboats began traveling up the Okanogan River, Riverside was the upstream limit of navigation during the high water season. Riverside was officially incorporated on December 22, 1913. Riverside is one of the few locations in the world where the mineral thulite is found, the others being Mitchell County, North Carolina; Orkland, Norway; and the Otago region of New Zealand.
Geography
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Image:Okanogan River at Riverside WA.jpg|The Okanogan River at Riverside
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According to the United States Census Bureau, the town has a total area of , of which, is land and is water. Sometimes considered to be part of Greater Omak, it is home to the Omak Airport.
Demographics
2010 census
As of the 2010 census, there were 280 people, 128 households, and 78 families living in the town. The population density was . There were 154 housing units at an average density of . The racial makeup of the town was 87.1% White, 7.5% Native American, 1.8% from other races, and 3.6% from two or more races. Hispanic or Latino of any race were 6.4% of the population.
There were 128 households, of which 23.4% had children under the age of 18 living with them, 45.3% were married couples living together, 10.9% had a female householder with no husband present, 4.7% had a male householder with no wife present, and 39.1% were non-families. 32.8% of all households were made up of individuals, and 10.9% had someone living alone who was 65 years of age or older. The average household size was 2.17 and the average family size was 2.68.
The median age in the town was 47 years. 20% of residents were under the age of 18; 5.7% were between the ages of 18 and 24; 21.8% were from 25 to 44; 30.4% were from 45 to 64; and 22.1% were 65 years of age or older. The gender makeup of the town was 50.0% male and 50.0% female.
2000 census
As of the 2000 census, there were 348 people, 143 households, and 95 families living in the town. The population density was 389.5 people per square mile (151.0/km<sup>2</sup>). There were 153 housing units at an average density of 171.2 per square mile (66.4/km<sup>2</sup>). The racial makeup of the town was 90.52% White, 0.29% African American, 5.17% Native American, 0.29% Asian, 1.15% from other races, and 2.59% from two or more races. Hispanic or Latino of any race were 2.87% of the population.