Trains along the Montclair-Boonton Line heading eastward usually originate at Hackettstown, Mount Olive, Lake Hopatcong, Dover, or Montclair State University, bound for either Hoboken Terminal or New York Penn Station.

Passengers can transfer at Secaucus Junction, Newark Broad Street Station, Montclair State University, or Dover to reach other destinations if necessary.

Lackawanna Terminal in Montclair closed in 1981, replaced by the new Bay Street station on the alignment that eventually would extend to the connection.

[5] The New York & Greenwood Lake Railway became a subsidiary of the Erie Railroad by 1884 and the remains of what was once its track is now the Walnut Street – Mountain View stretch of the Montclair-Boonton Line.

The original railroad extended farther, via the former alignment through Montclair, Glen Ridge, Bloomfield, Newark and reaching into Kearny, where it crossed the Hackensack River and the Meadowlands into Jersey City.

[18] On November 6, 1994, service was ceremonially extended along Conrail's Washington Secondary from Netcong station with the creation of the stops in Mount Olive and Hackettstown.

Three decades after the Erie's Main Line was realigned out of Passaic (in 1963), New Jersey Transit returned to the plan for the Montclair Connection.

"[22] On June 10, 2002, Governor of New Jersey James E. McGreevey announced a partnership with Montclair State University (MSU) as part of the Midtown Direct service.

[24] On October 20, 2004, the new Montclair State University Station at Little Falls opened in a ceremony led by executive director George Warrington and MSU president Susan Cole.

Montclair Township's proposal cited the benefits of weekend service to the communities along the line, including reduced traffic congestion and carbon footprint.

New Jersey Transit had received requests for weekend service since 2007, and denied them citing capacity issues and turning off electric power for bridge replacement.

[30] On September 30, 2009, New Jersey Transit announced service every two hours between Bay Street station and Hoboken Terminal, an approximately 35-minute trip.

The station dated back to 1905 as a transfer point between the New York & Greenwood Lake and its Caldwell Branch to Essex Fells, New Jersey.

[37] The Montclair-Boonton Line received serious damage from Hurricane Sandy on October 29–30, 2012, due to fallen trees blocking the tracks and bringing down catenary and signal wires.

[39] The Lackawanna Cut-Off, a project from Lake Hopatcong to Scranton, Pennsylvania, is to start off as the Andover Branch off Montclair-Boonton Line trains.

[39] Locals have expressed support for the extensions on the active Class I freight line, and would use automobiles to get to the stations' newly designed park and rides.

From there, trains use the alignment of the Morristown Line west through the Bergen Tunnels from Hoboken, over the Lower Hack Lift bridge across the Hackensack River.

[8] After Glen Ridge station, the Montclair-Boonton Line continues west before crossing under Bloomfield Avenue (County Route 506) and entering Montclair.

Bay Street is the newest station on the Montclair Branch portion of the Montclair-Boonton Line, built in 1981 to replace the nearby Lackawanna Terminal, which was becoming a "white elephant".

[47] The building was constructed in 1889 by the New York & Greenwood Lake as an irregular shape, similar to Benson Street station on the former Boonton Line alignment east of Montclair.

[11] After Mountain Avenue the tracks continue northward through Upper Montclair, passing through Mountainside Park and crossing Mount Hebron Road.

A short distance after Montclair State University, the tracks turn to the northwest, leave campus grounds and cross over Clove Road.

[8] West-northwest of the curve, the present line is back on the Delaware, Lackawanna and Western's Boonton Branch original alignment.

Just after crossing the Rockaway River the tracks pass the still existing DL&W Freight House and the West Boonton Yard, home of The United Railroad Historical Society of New Jersey.

[44] Mountain Lakes has a single low platform used for train service, while its station building, built in 1912 sits nearby as a restaurant.

After departing the Dover station, the Morristown Line catenary wires end about a half-mile west, near the US Route 46 overpass.

[29] After paralleling Interstate 80 out of Mount Arlington station, the line heads southwestward until turning northeastward through the community of Landing.

Netcong Station was also site of the junction to the former Sussex Branch built by the Delaware, Lackawanna and Western, discontinued from Branchville on July 13, 1966.

[53] Trackage south of Hackettstown is owned by Norfolk Southern and operated by the Dover and Delaware River Railroad as part of the Washington Secondary to Phillipsburg.

Electrified service west of Montclair State University, therefore, only serves Denville and Dover stations via the Morristown Line, along with the stretches in between.