The Borough of Mountainside, New Jersey, is located in Union County on 4.10 square miles of land. Built on the side of the Watchung mountains, Mountainside is a beautiful suburban community of single-family homes which has the advantage of being located within fast and efficient commuting distance to New York City, which is only 24 miles away. The 1990 Census showed a population of just over 6,600 people.

The tree-lined streets border Route 22 and have easy access to all major highways and airports providing residents with many commuting conveniences. Nearly a third of Mountainside is parkland, with half of the Watchung Reservation's 1,945 acres and most of the 147-acre Echo Lake Park, with its three large lakes, within its borders.

Mountainside has a free Public Library, Volunteer Fire Department, 3 churches and an elementary school, and a 50-Meter Olympic community pool. Mountainside shares its higher education with Berkeley Heights, at that town's Governor Livingston High School.

The commercial center is a quaint shopping village including banks, a florist, hardware store, pharmacy, bakery and other small specialty shops and food stores.

The Watchung Reservation and its woodland nature trails are a major recreational resource for the borough. Echo Lake Park offers fishing and boating and free concerts on summer evenings.