# Mountainside, New Jersey

Mountainside is a borough in Union County, in the U.S. state of New Jersey. The borough is located on a ridge in northern-central New Jersey, within the Raritan Valley and Rahway Valley regions in the New York metropolitan area. As of the 2020 United States census, the borough's population was 7,020, an increase of 335 (+5.0%) from the 2010 census count of 6,685, which in turn reflected an increase of 83 (+1.3%) from the 6,602 counted in the 2000 census.
Mountainside was incorporated as a borough on September 25, 1895, from portions of Westfield Township, based on the results of a referendum held the previous day.
New Jersey Monthly magazine ranked Mountainside as its 16th best place to live in its 2008 rankings of the "Best Places To Live" in New Jersey, as well as eighth in the 2010 list.

## History

In 1958, part of Nike missile battery (NY-73) was installed, with the missile launchers themselves in Mountainside while the radar station was installed in Berkeley Heights. It remained in operation until 1963. Remnants of the control site are located adjacent to Governor Livingston High School, while the part of Watchung Reservation that was cleared in order to accommodate the missile launchers became the Watchung Stables.

## Geography

According to the United States Census Bureau, the borough had a total area of 4.04 square miles (10.47 km$^2$), including 4.00 square miles (10.35 km$^2$) of land and 0.05 square miles (0.12 km$^2$) of water (1.11%).
Mountainside is bordered by the Union County municipalities of Summit to the north, by Springfield Township to the east, by Westfield to the south and by Berkeley Heights and Scotch Plains to the west.

## Demographics
### 2010 census

The 2010 United States census counted 6,685 people, 2,468 households, and 1,866 families in the borough. The population density was 1,668.0 per square mile (644.0/km$^2$). There were 2,558 housing units at an average density of 638.3 per square mile (246.4/km$^2$). The racial makeup was 91.31% (6,104) White, 1.97% (132) Black or African American, 0.00% (0) Native American, 4.94% (330) Asian, 0.00% (0) Pacific Islander, 0.42% (28) from other races, and 1.36% (91) from two or more races. Hispanic or Latino of any race were 6.09% (407) of the population.
Of the 2,468 households, 30.8% had children under the age of 18; 66.7% were married couples living together; 6.5% had a female householder with no husband present and 24.4% were non-families. Of all households, 21.6% were made up of individuals and 15.6% had someone living alone who was 65 years of age or older. The average household size was 2.64 and the average family size was 3.10.
23.2% of the population were under the age of 18, 4.8% from 18 to 24, 18.2% from 25 to 44, 30.0% from 45 to 64, and 23.7% who were 65 years of age or older. The median age was 47.2 years. For every 100 females, the population had 92.7 males. For every 100 females ages 18 and older there were 88.1 males.
The Census Bureau's 2006–2010 American Community Survey showed that (in 2010 inflation-adjusted dollars) median household income was $116,210 (with a margin of error of +/− $22,182) and the median family income was $135,086 (+/− $14,679). Males had a median income of $95,030 (+/− $9,312) versus $58,818 (+/− $8,974) for females. The per capita income for the borough was $52,844 (+/− $5,530). About 1.5% of families and 3.5% of the population were below the poverty line, including 3.1% of those under age 18 and 8.1% of those age 65 or over.

### 2000 census

As of the 2000 United States census there were 6,602 people, 2,434 households, and 1,925 families residing in the borough. The population density was 1,640.8 inhabitants per square mile (633.5/km$^2$). There were 2,478 housing units at an average density of 615.8 per square mile (237.8/km$^2$). The racial makeup of the borough was 95.09% White, 0.94% African American, 0.09% Native American, 2.80% Asian, 0.06% Pacific Islander, 0.27% from other races, and 0.74% from two or more races. Hispanic or Latino of any race were 3.01% of the population.
There were 2,434 households, out of which 29.3% had children under the age of 18 living with them, 71.9% were married couples living together, 5.3% had a female householder with no husband present, and 20.9% were non-families. 17.9% of all households were made up of individuals, and 11.9% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 2.95.
In the borough the population was spread out, with 21.1% under the age of 18, 3.8% from 18 to 24, 22.9% from 25 to 44, 27.3% from 45 to 64, and 24.9% who were 65 years of age or older. The median age was 46 years. For every 100 females, there were 89.2 males. For every 100 females age 18 and over, there were 87.1 males.
The median income for a household in the borough was $97,195, and the median income for a family was $105,773. Males had a median income of $78,595 versus $52,667 for females. The per capita income for the borough was $47,474. About 2.0% of families and 3.0% of the population were below the poverty line, including 1.9% of those under age 18 and 2.9% of those age 65 or over.

## Government
### Local government

Mountainside is governed by a Mayor-Council form of government as authorized through the Option Municipal Charter Law (commonly called the Faulkner Act). The township is one of 71 municipalities (of the 564) statewide that use this form of government. The governing body is comprised of the mayor and the six-member borough council. Under this form of local government, the mayor is elected for a term of four years and there borough council members are elected for three-year terms, with two seats coming up for election each year in a three-year cycle. Both the mayor and Borough Council are elected at-large, that is, to represent the entire community. Elections for all officials in Mountainside are conducted on a partisan basis during the November General Election.
As of 2024, the mayor of Mountainside is Republican Paul N. Mirabelli, whose term of office ends on December 31, 2027. Members of the Borough Council are Deanna Andre (R, 2026), René Dierkes (R, 2025), Steven Matejek (R, 2026), Robert W. Messler (R, 2024), Donna Pacifico (R, 2025), and Donald Rinaldo Jr. (R, 2024).

### Federal, state and county representation

Mountainside is located in the 7th Congressional District and is part of New Jersey's 21st state legislative district.
For the 119th United States Congress, New Jersey's 7th congressional district is represented by Thomas Kean Jr. (R, Westfield). New Jersey is represented in the United States Senate by Democrats Cory Booker (Newark, term ends 2027) and Andy Kim (Moorestown, term ends 2031).
For the 2024-2025 session, the 21st legislative district of the New Jersey Legislature is represented in the State Senate by Jon Bramnick (R, Westfield) and in the General Assembly by Michele Matsikoudis (R, New Providence) and Nancy Munoz (R, Summit).
Union County is governed by a Board of County Commissioners, whose nine members are elected at-large to three-year terms of office on a staggered basis with three seats coming up for election each year, with an appointed County Manager overseeing the day-to-day operations of the county. At an annual reorganization meeting held in the beginning of January, the board selects a Chair and Vice Chair from among its members. As of 2025, Union County's County Commissioners are:
Rebecca Williams (D, Plainfield, 2025), Joesph Bodek (D, Linden, 2026), James E. Baker Jr. (D, Rahway, 2027), Michele Delisfort (D, Union Township, 2026), Sergio Granados (D, Elizabeth, 2025), Bette Jane Kowalski (D, Cranford, 2025), Vice Chair Lourdes M. Leon (D, Elizabeth, 2026), Alexander Mirabella (D, Fanwood, 2027) and Chair Kimberly Palmieri-Mouded (D, Westfield, 2027).
Constitutional officers elected on a countywide basis are: Clerk Joanne Rajoppi (D, Union Township, 2025), Sheriff Peter Corvelli (D, Kenilworth, 2026) and Surrogate Christopher E. Hudak (D, Clark, 2027).

### Politics

As of March 2011, there were a total of 4,744 registered voters in Mountainside, of which 1,201 (25.3% vs. 41.8% countywide) were registered as Democrats, 1,568 (33.1% vs. 15.3%) were registered as Republicans and 1,974 (41.6% vs. 42.9%) were registered as Unaffiliated. There was one voter registered to another party. Among the borough's 2010 Census population, 71.0% (vs. 53.3% in Union County) were registered to vote, including 92.5% of those ages 18 and over (vs. 70.6% countywide).
United States presidential election results for Mountainside :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 2,275 | 51.44% | 2,074 | 46.89% | 74 | 1.67% |
| 2020 | 2,251 | 49.64% | 2,239 | 49.37% | 45 | 0.99% |
| 2016 | 2,094 | 54.35% | 1,641 | 42.59% | 118 | 3.06% |
| 2012 | 2,100 | 59.47% | 1,401 | 39.68% | 30 | 0.85% |
| 2008 | 2,331 | 60.33% | 1,500 | 38.82% | 33 | 0.85% |
| 2004 | 2,215 | 57.76% | 1,589 | 41.43% | 31 | 0.81% |
In the 2012 presidential election, Republican Mitt Romney received 2,100 votes (59.2% vs. 32.3% countywide), ahead of Democrat Barack Obama with 1,401 votes (39.5% vs. 66.0%) and other candidates with 30 votes (0.8% vs. 0.8%), among the 3,548 ballots cast by the borough's 4,940 registered voters, for a turnout of 71.8% (vs. 68.8% in Union County). In the 2008 presidential election, Republican John McCain received 2,331 votes (60.0% vs. 35.2% countywide), ahead of Democrat Barack Obama with 1,500 votes (38.6% vs. 63.1%) and other candidates with 33 votes (0.8% vs. 0.9%), among the 3,888 ballots cast by the borough's 4,911 registered voters, for a turnout of 79.2% (vs. 74.7% in Union County). In the 2004 presidential election, Republican George W. Bush received 2,215 votes (58.0% vs. 40.3% countywide), ahead of Democrat John Kerry with 1,561 votes (40.8% vs. 58.3%) and other candidates with 31 votes (0.8% vs. 0.7%), among the 3,822 ballots cast by the borough's 4,796 registered voters, for a turnout of 79.7% (vs. 72.3% in the whole county).
In the 2017 gubernatorial election, Republican Kim Guadagno received 1,443 votes (57.7% vs. 32.6% countywide), ahead of Democrat Phil Murphy with 1,020 votes (40.8% vs. 65.2%), and other candidates with 39 votes (1.6% vs. 2.1%), among the 2,602 ballots cast by the borough's 5,190 registered voters, for a turnout of 50.1%. In the 2013 gubernatorial election, Republican Chris Christie received 69.9% of the vote (1,595 cast), ahead of Democrat Barbara Buono with 29.0% (661 votes), and other candidates with 1.1% (26 votes), among the 2,320 ballots cast by the borough's 4,860 registered voters (38 ballots were spoiled), for a turnout of 47.7%. In the 2009 gubernatorial election, Republican Chris Christie received 1,754 votes (61.8% vs. 41.7% countywide), ahead of Democrat Jon Corzine with 842 votes (29.6% vs. 50.6%), Independent Chris Daggett with 204 votes (7.2% vs. 5.9%) and other candidates with 17 votes (0.6% vs. 0.8%), among the 2,840 ballots cast by the borough's 4,827 registered voters, yielding a 58.8% turnout (vs. 46.5% in the county).

## Education

The Mountainside School District serves public school students in pre-kindergarten through eighth grade. As of the 2022–23 school year, the district, comprised of two schools, had an enrollment of 747 students and 71.6 classroom teachers (on an FTE basis), for a student–teacher ratio of 10.4:1. Schools in the district (with 2022–23 enrollment data from the National Center for Education Statistics) are Beechwood School with 269 students in grades PreK-2 and Deerfield School with 467 students in grades 3-8.
Public school students in ninth through twelfth grades attend Governor Livingston High School in Berkeley Heights, as part of a sending/receiving relationship with the Berkeley Heights Public Schools that is covered by an agreement that runs through the end of 2021–2022 school year. As of the 2022–23 school year, the high school had an enrollment of 936 students and 88.2 classroom teachers (on an FTE basis), for a student–teacher ratio of 10.6:1. Students also have the choice to attend the programs of the Union County Vocational Technical Schools, which serve students from across Union County.

## Emergency medical services

Emergency Medical Services for the borough of Mountainside is provided by the Mountainside Rescue Squad during nights and weekends. Since 2006, weekday daytime coverage has been provided by Atlantic Ambulance EMS, which has a paramedic unit stationed in Mountainside.

## Transportation
### Roads and highways

As of May 2010, the borough had a total of 41.12 miles (66.18 km) of roadways, of which 29.74 miles (47.86 km) were maintained by the municipality, 8.75 miles (14.08 km) by Union County and 2.63 miles (4.23 km) by the New Jersey Department of Transportation.
U.S. Route 22 and Interstate 78 are the main highways running through Mountainside.

### Public transportation

NJ Transit Bus Operations routes 114 and 117 provide service to the Port Authority Bus Terminal in Midtown Manhattan in New York City while routes 65 and 66 travel to Downtown Newark, all making local stops at points in proximate communities. An early use of bus rapid transit in New Jersey, a BBS (bus bypass shoulder, originally called a BOS or bus on shoulder lane) has been in operation for many years. Unlike most municipalities along Route 22, zoning in Mountainside does not allow for much commercial development adjacent to the freeway. For a one-mile stretch in the town, the eastbound shoulder on the arterial road can be used for peak hour buses. In 2012, the New Jersey Department of Transportation (NJDOT) regulated the BBS as an exclusive bus lane from 6 to 7:30am. In 2009, NJDOT funded construction of two bus turnouts along the road in nearby Union.
Newark Liberty International Airport is approximately 11 miles (18 km) east of Mountainside.
NJ Transit rail service is accessible via Summit station, and it has frequent direct service to New York Penn Station. The station is located around 2 miles (3.2 km) from the center of Mountainside, and Westfield station, which is about 4 miles (6.4 km) away, is also nearby.

## Notable people

People who were born in, residents of, or otherwise closely associated with Mountainside include:
* Erika Amato (born 1969), singer and actress who was a founding member of the band Velvet Chain
* John W. Campbell (1910–1971), science fiction writer who was editor of Astounding Science Fiction from 1937 until his death
* Bob Clotworthy (1931–2018), diver who won the bronze medal in the men's springboard event at the 1952 Summer Olympics in Helsinki and won the gold medal in Melbourne at the 1956 games
* Laurie Collyer (born 1967), film director, best known for Sherrybaby
* Angelo DeCarlo (1902–1973), member of the New York Genovese crime family
* Harry Devlin (born 1918), cartoonist for magazines such as Collier's Weekly
* Ina Golub (1938–2015), fiber artist who specialized in Judaica
* Charles J. Irwin (1930–2005), politician who served in the New Jersey General Assembly from the 9th at-large district from 1968 to 1971
* Bitty Schram (born 1968), actress who appeared on Monk and in the 1992 film A League of Their Own
* Dale Torborg (born 1971), conditioning coordinator for the Chicago White Sox and former professional wrestler best known for his time in World Championship Wrestling
* Jeff Torborg (born 1941), former Major League Baseball player and manager
* Hela Yungst (1950–2002), television entertainer and beauty pageant winner