Three Forks is a city in Gallatin County, Montana, United States and is located within the watershed valley system of both the Missouri and Mississippi rivers drainage basins — and is historically considered the birthplace or start of the Missouri River. The population was 1,869 at the 2010 census. The city of Three Forks is named so because it lies geographically near the point, in nearby Missouri Headwaters State Park, where the Jefferson, Madison, and Gallatin Rivers converge to form the Missouri River — the longest single river in North America, as well as the major portion of the Missouri-Mississippi River System from the headwaters near Three Forks to its discharge into the Gulf of Mexico. Three Forks is part of the Bozeman, MT Micropolitan Statistical Area of approximately 100,000 people and located thirty miles west of Bozeman.
Three Forks is located at 45°53′29″N 111°33′6″W / 45.89139°N 111.55167°W / 45.89139; -111.55167 (45.891334, -111.551532).
According to the United States Census Bureau, the city has a total area of 1.50 square miles (3.88 km), of which, 1.44 square miles (3.73 km) is land and 0.06 square miles (0.16 km) is water.
As of the census of 2010, there were 1,869 people, 785 households, and 524 families residing in the city. The population density was 1,297.9 inhabitants per square mile (501.1/km). There were 850 housing units at an average density of 590.3 per square mile (227.9/km). The racial makeup of the city was 98.1% White, 0.2% African American, 0.4% Native American, 0.5% Asian, and 0.9% from two or more races. Hispanic or Latino of any race were 2.1% of the population.
There were 785 households of which 31.1% had children under the age of 18 living with them, 51.2% were married couples living together, 9.0% had a female householder with no husband present, 6.5% had a male householder with no wife present, and 33.2% were non-families. 28.4% of all households were made up of individuals and 11.3% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 2.90.
The median age in the city was 40.8 years. 24.8% of residents were under the age of 18; 6.4% were between the ages of 18 and 24; 24.5% were from 25 to 44; 28.4% were from 45 to 64; and 15.8% were 65 years of age or older. The gender makeup of the city was 49.9% male and 50.1% female.
As of the census of 2000, there were 1,728 people, 686 households, and 469 families residing in the city. The population density was 1,360.7 people per square mile (525.3/km²). There were 726 housing units at an average density of 571.7 per square mile (220.7/km²). The racial makeup of the city was 97.57% White, 1.10% Native American, 0.17% Asian, 0.23% Pacific Islander, 0.35% from other races, and 0.58% from two or more races. Hispanic or Latino of any race were 1.33% of the population.
There were 686 households out of which 35.4% had children under the age of 18 living with them, 59.3% were married couples living together, 5.8% had a female householder with no husband present, and 31.5% were non-families. 26.7% of all households were made up of individuals and 12.1% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 3.08.
In the city, the population was spread out with 28.4% under the age of 18, 6.0% from 18 to 24, 28.9% from 25 to 44, 21.8% from 45 to 64, and 15.0% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 102.8 males. For every 100 females age 18 and over, there were 102.6 males.
The median income for a household in the city was $34,212, and the median income for a family was $39,938. Males had a median income of $30,086 versus $19,196 for females. The per capita income for the city was $15,362. About 5.5% of families and 7.7% of the population were below the poverty line, including 6.6% of those under age 18 and 6.7% of those age 65 or over.