Precinct 142C includes the part of the western side Norwalk south of the Connecticut Turnpike (I-95) and north of the line of Hunt Street, Witch Lane and Old Trolley Place in Rowayton. The eastern line is as shown on the map and runs along Gray Rock Road, Ryan Avenue, Ely Avenue, Dr. Martin Luther King Jr. Drive, Bouton Street, Glasser Street, Arbor Drive, Frances Avenue, McAllister Avenue, Avenue D, Morton Street, Senga Road and Scribner Avenue to the Connecticut Turnpike.

Precinct 142C votes at Brookside School, which was not previously used in State/Federal Elections. Roton Middle School, which is also in the precinct, is no longer being used as a polling place.