According to the United States Census Bureau, the township has a total area of. of it is land and of it is water. It is drained by the Delaware River, which forms its eastern boundary separating it from New Jersey. Its natural northwest boundary is Blue Mountain. Its villages include Centerville, Five Points, Hartzells Ferry, Johnsonville, Mount Bethel, North Bangor, and Slateford. Its numbered routes are 191, 512, and 611.
As of the census of 2000, there were 6,063 people, 2,363 households, and 1,732 families residing in the township. The population density was 139.7 people per square mile. There were 2,574 housing units at an average density of 59.3/sq mi. The racial makeup of the township was 97.89% White, 0.69% African American, 0.13% Native American, 0.49% Asian, 0.21% from other races, and 0.58% from two or more races. Hispanic or Latino of any race were 1.39% of the population. There were 2,363 households, out of which 28.8% had children under the age of 18 living with them, 63.4% were married couplesliving together, 6.1% had a female householder with no husband present, and 26.7% were non-families. 21.7% of all households were made up of individuals, and 8.9% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 2.96. In the township the population was spread out, with 22.8% under the age of 18, 6.2% from 18 to 24, 28.3% from 25 to 44, 26.8% from 45 to 64, and 15.9% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 100.8 males. For every 100 females age 18 and over, there were 100.6 males. The median income for a household in the township was $45,617, and the median income for a family was $54,692. Males had a median income of $38,914 versus $23,906 for females. The per capita income for the township was $21,116. About 4.6% of families and 6.3% of the population were below the poverty line, including 3.3% of those under age 18 and 15.7% of those age 65 or over. History Old Mount Bethel was one of the oldest settled areas in Northampton County. Included within in its jurisdiction was the Old Hunter Settlement, founded by the Ulster-Scots around 1730. That same year Old Mount Bethel was erected a town. After the walking purchase of 1737 between the Penn family and the Leni Lenape was completed, Old Mount Bethel was established within the County of Bucks. In 1752 Bucks County was divided and Northampton County was established, geographically placing Old Mount Bethel within the boundaries of Northampton County.
