Waterloo is a city in Linn County, Oregon, United States. The population was 229 at the 2010 census.
The city's name, a joking reference to the Battle of Waterloo, stemmed from a 19th-century court decision that settled a land dispute at Kees Mill along the South Santiam River.
The federal government established a post office at Waterloo on January 5, 1875. S. D. Granger was its first postmaster. The post office closed in 1974.
Geography
According to the United States Census Bureau, the town has a total area of , all land. The closest city is Lebanon.
Climate
This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above . According to the Köppen Climate Classification system, Waterloo has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps.
Demographics
2010 census
As of the census of 2010, there were 229 people, 79 households, and 62 families living in the town. The population density was . There were 87 housing units at an average density of . The racial makeup of the town was 96.5% White, 1.3% Native American, 0.4% from other races, and 1.7% from two or more races. Hispanic or Latino of any race were 5.7% of the population.
There were 79 households, of which 29.1% had children under the age of 18 living with them, 62.0% were married couples living together, 11.4% had a female householder with no husband present, 5.1% had a male householder with no wife present, and 21.5% were non-families. 17.7% of all households were made up of individuals, and 3.8% had someone living alone who was 65 years of age or older. The average household size was 2.90 and the average family size was 3.27.