Mountain Top consists of the entirety of Dorrance Township, Fairview Township, Rice Township, Slocum Township, and Wright Township.
Though it is generally accepted that the area's proper name is "Mountain Top," there has been some debate about whether it should actually be "Mountaintop." The local historical society[1] uses the spelling "Mountain Top". The United States Postal Service uses the spelling "Mountain Top" for ZIP Code 18707 and the Pennsylvania Department of Transportation spells it Mountain Top on a Pennsylvania driver's licence. The local newspaper, however, the Mountaintop Eagle [2], uses the Mountaintop spelling in both its title as well as any reference to its location.
As of the census of 2000, there were 15,269 people, 5,556 households, and 4,394 families residing in the CDP. The population density was 224.0 people per square mile (86.5/km²). There were 5,774 housing units at an average density of 84.7/sq mi (32.7/km²). The racial makeup of the CDP was 97.02% White, 0.54% African American, 0.03% Native American, 1.62% Asian, 0.24% from other races, and 0.56% from two or more races. Hispanic or Latino of any race were 1.08% of the population.
There were 5,556 households out of which 36.8% had children under the age of 18 living with them, 68.2% were married couples living together, 8.1% had a female householder with no husband present, and 20.9% were non-families. 18.4% of all households were made up of individuals and 8.5% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.10.
In the CDP the population was spread out with 26.0% under the age of 18, 6.0% from 18 to 24, 28.7% from 25 to 44, 25.7% from 45 to 64, and 13.6% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 95.5 males. For every 100 females age 18 and over, there were 92.9 males.
The median income for a household in the CDP was $51,655, and the median income for a family was $58,588. Males had a median income of $41,271 versus $26,346 for females. The per capita income for the CDP was $22,480. About 2.9% of families and 3.4% of the population were below the poverty line, including 3.7% of those under age 18 and 5.4% of those age 65 or over.
About 26.5% of the population has Polish roots.