Town guide · Somerset County
Living in Rocky Hill, NJ
Rocky Hill is a 19th century village of about 0.6 square miles on the Millstone River. Much of it is a historic district, and it looks much as it did a century ago, with the Delaware and Raritan Canal and Washington's Rockingham headquarters close by.
- County
- Somerset
- Population
- About 740 (2020 census)
- Size
- About 0.6 square miles
- Setting
- Historic village on the Millstone River
- Main roads
- County Route 518, connecting to U.S. Route 206 and Route 27
First things first
Its own borough, not part of Montgomery
Rocky Hill was Montgomery Township's first village. In 1889 it was carved out of Montgomery and became its own borough, with its own government and its own property taxes.
Rocky Hill still borders Montgomery and Franklin Township, so a nearby home can be in a different town even when it feels like the same place. We always confirm the actual municipality and block and lot.
The village
A village that kept its shape
Rocky Hill grew around a transportation crossroads on the Millstone River, starting with early mills around 1712. The canal and the railroad brought its strongest growth, and when industry declined around 1900 the village largely stopped changing. That is why so much of it still looks the way it did a century ago. The borough is named for the Rocky Hill Ridge.
The Rocky Hill Historic District covers 176 acres and 145 buildings and was added to the National Register in 1982.
- Washington Street: Mostly inside the local historic district, it leads to the Millstone River and the canal crossing.
- Historic district streets: Crescent Avenue, Grove Street, Park Avenue, Reeve Road and Skillman Avenue are fully inside the local historic district, along with most of Washington Street.
- Van Horne Park: The borough park, which takes up a large share of Rocky Hill's land.
Homes
What you will find
- Historic village homes: Many residences sit inside the local historic district, in a village that grew through the 19th century.
- Newer homes: Newer construction in the district is expected to be visually compatible with its historic neighbors.
Worth knowing: A large share of Rocky Hill homes are in the local historic district, governed by a preservation ordinance adopted in 1983. Exterior changes visible from a public street, such as a new roof, a rebuilt porch or new shutters, need approval through the Planning Board and its Historic Preservation Committee. Ordinary repairs with in kind materials and repainting do not. We tell buyers about this before they write an offer.
Property taxes
What taxes look like in Rocky Hill
- 2.071%2025 effective tax rate, as a share of market value
- $12,4352025 average residential tax bill
A home worth $600,000 on today's market would pay roughly $12,426 a year at Rocky Hill's 2025 effective rate. Your actual bill depends on your assessment, so we pull the real tax record for any home you are considering.
Source: New Jersey Division of Taxation, 2025 general and effective tax rates. Rates are set each year.
Getting around
Roads and commuting
County Route 518 runs about a mile through the borough, reaching U.S. Route 206 to the west and Route 27 to the east. No limited access highway runs near the borough. Drivers reach Interstate 287, Interstate 295 and the New Jersey Turnpike by way of Route 206, Route 27 and other local roads. There is no train station in Rocky Hill. Rocky Hill sits on the Millstone Valley Scenic Byway, a 23 mile loop along the Millstone River and the canal.
Places worth knowing
Parks, landmarks and open space
- Rocky Hill Historic District: A 176 acre National Register district of 145 buildings, including a former schoolhouse.
- Van Horne Park: The borough's park, which takes up a large portion of Rocky Hill.
- Delaware and Raritan Canal: At the Washington Street crossing, a parking area gives access to the canal towpath and the reconstructed foundation of the Rocky Hill bridge tender's house.
- Rockingham: The c.1710 house where George Washington wrote his Farewell Orders to the Army in 1783, now about a mile south of the Washington Street canal crossing, toward Kingston.
Common questions
Questions people ask us about Rocky Hill
What are property taxes in Rocky Hill, NJ?
Rocky Hill Borough's 2025 effective tax rate is 2.071 percent of market value, and the average residential tax bill is $12,435, according to the New Jersey Division of Taxation. Actual bills depend on each home's assessment.
Is Rocky Hill part of Montgomery Township?
No. Rocky Hill was carved out of Montgomery in 1889 and is its own borough, with its own government and property taxes. It borders Montgomery and Franklin Township.
Is all of Rocky Hill a historic district?
Not all of it, but a significant number of homes are in the local historic district. Owners there need approval for exterior changes visible from a public street, though repainting and ordinary in kind repairs do not need approval.
Where is Rockingham, Washington's headquarters?
Rockingham is the house where George Washington wrote his Farewell Orders to the Army in late October 1783. It has been moved three times since 1896 and now stands just north of Kingston, about a mile south of Rocky Hill's Washington Street canal crossing.
How far is Rocky Hill from a major highway?
County Route 518 runs through Rocky Hill and connects to U.S. Route 206 to the west and Route 27 to the east. There is no limited access highway nearby, so trips to Interstate 287, Interstate 295 or the New Jersey Turnpike start on Route 206, Route 27 or other local roads.
Nearby towns
Towns that border Rocky Hill
Buying or selling in Rocky Hill?
Know the historic rules before you list
In Rocky Hill, a new roof or a rebuilt porch facing the street may need Historic Preservation Committee approval. We explain those rules up front, before an offer is written, and then talk through your options.
Call or text either of us directly.