Somerset County vs. Warren County
Two New Jersey counties, side by side. They don’t share a border: Hunterdon and Morris lie between them.
Side by side
Facts from official county, state and federal sources and other published sources. Each county’s guide has more.
| Fact | Somerset County | Warren County |
|---|---|---|
| County seat | Somerville | Belvidere |
| Municipalities | 21 municipalities Twelve boroughs and nine townships make up Somerset County. | 22 municipalities Three towns, two boroughs and 17 townships make up Warren County. |
| Land area | 301.9 square miles | 356.5 square miles |
| Landscape | The North and South Branches of the Raritan meet here. The Watchung Mountains, the Somerset Hills and the Sourland Mountain frame river valleys and farmland. | Ridges and valleys running northeast to southwest, from Kittatinny Mountain to Pohatcong Mountain, drained by the Musconetcong, Pequest and Paulinskill into the Delaware. |
| Downtowns | Somerville’s Main Street and pedestrian Division Street at the county seat, Bound Brook’s Main Street by its station, and Millstone, once the county seat. | Hackettstown’s Main Street, Washington Borough’s crossroads downtown, Phillipsburg’s Union Square and historic district, and Belvidere’s courthouse square. |
| Rail | Raritan Valley Line: Bound Brook, Bridgewater, Somerville, Raritan, North Branch. Gladstone Branch: Basking Ridge, Lyons, Bernardsville, Far Hills, Peapack, Gladstone. | Hackettstown station, the western end of NJ Transit’s Montclair-Boonton Line and Morris & Essex Lines, with weekday trains toward Hoboken and New York. |
| Highways | I-78 and I-287, which meet in Bridgewater and Bedminster, plus US 22, US 202, US 206 and Route 28. | I-78 and I-80, US 22 and US 46, and Routes 31, 57 and 94. |
| Outdoors | Duke Island Park on the Raritan in Bridgewater, the Sourland Mountain Preserve in Hillsborough, and Duke Farms, with more than 18 miles of trails. | Delaware Water Gap National Recreation Area, Stephens State Park, and six county parks along the Morris Canal Greenway. |
| Featured towns | Somerville, Hillsborough, and BridgewaterTown guides coming soon | Hackettstown, Washington Borough, and PhillipsburgTown guides coming soon |
| Full guide | Read the Somerset County guide | Read the Warren County guide |
Land area and municipalities: U.S. Census Bureau. The other rows: county, municipal, NJ Transit, NJDOT, other state and federal sources, and local organizations, checked in October 2026.
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Read the full guides
Each guide maps every municipality in the county, with its featured towns and facts at a glance.
More comparisons: Hunterdon vs. Somerset, Hunterdon vs. Warren, Morris vs. Somerset, and Morris vs. Warren
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