Three Rivers derives its name from its location at the confluence of the St. Joseph River and two tributaries, the Rocky and Portage rivers.[6] The St. Joseph River flows into Lake Michigan.
According to the United States Census Bureau, the city has a total area of 5.66 square miles (14.66 km2), of which 5.40 square miles (13.99 km2) is land and 0.26 square miles (0.67 km2) is water.[7]
As of 2000 the median income for a household in the city was $32,460, and the median income for a family was $36,272. Males had a median income of $31,849 versus $23,659 for females. The per capita income for the city was $16,279. About 16.2% of families and 19.3% of the population were below the poverty line, including 25.5% of those under age 18 and 9.4% of those age 65 or over.
2010 census
As of the census[11] of 2010, there were 7,811 people. The 49093 Three Rivers zip code population as of 2010 stands at just shy of 20,000 people 3,048 households, and 1,862 families residing in the city. The population density was 1,446.5 inhabitants per square mile (558.5/km2). There were 3,519 housing units at an average density of 651.7 per square mile (251.6/km2). The racial makeup of the city was 82.6% White, 10.1% African American, 0.6% Native American, 0.9% Asian, 1.8% from other races, and 4.0% from two or more races. Hispanic or Latino of any race were 5.2% of the population.
There were 3,048 households, of which 36.9% had children under the age of 18 living with them, 35.2% were married couples living together, 19.7% had a female householder with no husband present, 6.2% had a male householder with no wife present, and 38.9% were non-families. 32.5% of all households were made up of individuals, and 12.5% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.15.
The median age in the city was 31.5 years. 28.5% of residents were under the age of 18; 10.6% were between the ages of 18 and 24; 27.3% were from 25 to 44; 21.5% were from 45 to 64; and 12% were 65 years of age or older. The gender makeup of the city was 47.7% male and 52.3% female.
^"Station: Three Rivers, MI". U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991-2020). National Oceanic and Atmospheric Administration. Retrieved September 4, 2021.
