Population111,540 (July 1, 2025 Census estimate)
Waterpower And A Planned Public Square
Jefferson County, New YorkWatertown anchors Jefferson County, where the Black River’s waterpower helped shape the city’s early industry. The county seat’s public square and the arrival of papermaking provide concrete ways to connect civic planning with the working history of this part of northern New York. The U.S. Census Bureau estimated 111,540 residents in Jefferson County, New York, on July 1, 2025.
Jefferson County at a Glance
Population111,540 (July 1, 2025 Census estimate)
County SeatWatertown
StateNew York
Established1805 (organized; NACo County Explorer)
ZIP CodesVary by address
Total Area, Including Water1,857.357 square miles, including water (2020 Census geography)
Road InformationState transportation resources below
Area CodesSee local phone listings
Shop - Dine - Discover
Meet Local Businesses
Support the businesses that help make our communities thrive. From family-owned shops and restaurants to trusted local services, discover businesses worth visiting throughout the county.
Discover Jefferson County
Jefferson County
Jefferson County was established in 1805 from part of Oneida County and named for Thomas Jefferson. Watertown became the seat, with its public square forming an important civic reference. The city's history identifies an early paper mill in 1808, connecting the Black River's waterpower with industrial development. County resources also describe dairy agriculture as part of the wider regional story. These themes link the administrative center to both river-based manufacturing and the countryside beyond it.
Start with Watertown's public-square and river history, then use local resources to follow a more specific industrial or agricultural theme. The paper-mill story helps explain why the Black River mattered beyond scenery. Historic industrial locations should not be assumed open for a visit, so select current public destinations through their own information. A county-focused outing can connect the civic center with the working landscape rather than treating either as a complete picture on its own.
What Shapes Us
Place And Character
The county seat's public square and the arrival of papermaking provide concrete ways to connect civic planning with the working history of this part of northern New York.
The Local Story
Jefferson County was established in 1805 from part of Oneida County and named for Thomas Jefferson. Watertown became the seat, with its public square forming an important civic reference.
Explore The County
Start with Watertown's public-square and river history, then use local resources to follow a more specific industrial or agricultural theme.
Discover the community built around river power and public places.
A Closer Look
Jefferson County
Places and perspectives from Jefferson County
New York State Department of Transportation
New York & Atlantic Railway Receives $6.5 Million Federal CRISI Grant, Joining State and Private Funding in a $10.9 Million Partnership to Upgrade Four Locomotives with Cleaner Technology
Read the Story Oct 28, 2026 • 2 min read
Around Jefferson County
Stories from every corner of Jefferson County.
New York & Atlantic Railway Receives $6.5 Million Federal CRISI Grant, Joining State and Private Funding in a $10.9 Million Partnership to Upgrade Four Locomotives with Cleaner Technology
Oct 28, 2026 • 2 min read
State Department of Transportation to Host Two Public Information Meetings for Proposed Projects in Towns of Wirt and Burns, Allegany County
Oct 28, 2026 • 2 min read
State Department of Transportation Announces Completion of $19.9 Million Bridge Replacement Project in Hamilton County
Oct 28, 2026 • 2 min read
Governor Hochul Announces Completion of Major Work on the Transformative Van Wyck Expressway Project
Oct 26, 2026 • 2 min read
War on Potholes: Governor Hochul Fills the One Millionth Pothole on State Roads in 2026
Oct 22, 2026 • 2 min read
Shop - Dine - Discover
Meet Local Businesses
Support the businesses that help make our communities thrive. From family-owned shops and restaurants to trusted local services, discover businesses worth visiting throughout the county.
County Resources
Find the Right Local Connection
Start with the organization responsible for the service you need. Follow its official link for current requirements, office locations and availability.
County photographs from Wikimedia Commons; images may be cropped for display.
- Looking up in Boldt Castle in Alexandria Bay, NY, USA.jpg — Ram samudrala. CC BY-SA 4.0. Own work
- Boldt Castle Exterior.jpg — Stilfehler 17:24, 11 October 2007 (CEST). CC BY-SA 1.0. Own work
- Boldt Castle Power House 1.jpg — Stilfehler 17:27, 11 October 2007 (CEST). CC BY-SA 1.0. Own work
New York statewide resources
Government
Start here for official New York State services, agency information, records, taxes, licensing and local-government resources.
- NY.gov Service Finder — Search state services by topic, including business, health, housing, licenses, transportation and social programs.
- All New York State Services — Browse the statewide directory of online services and programs.
- New York State Agencies — Find state departments, offices, authorities and commissions.
- New York State Counties — Official statewide county directory and county links.
- Department of State — Business filings, licensing, local government, consumer protection and related services.
- Open NY — Search New York State public datasets and open-government information.
- Department of Taxation and Finance — Individual and business tax information, forms, filing and online services.
- New York State Archives — Government records, historical records, research tools and records-management resources.
Schools
Public school contacts
Selected local schools from the NCES 2024-2025 directory. Contact the school or district to confirm enrollment, attendance boundaries and current services; this is not a complete school list.
Alexandria Central Elementary School – Elementary; grades PK-06. 34 BOLTON AVE, ALEXANDRIA BAY, NY 13607. 315-482-9971.
Belleville Henderson Central School – Other; grades PK-12. 8372 COUNTY RT 75, BELLEVILLE, NY 13611. 315-846-5121.
Black River School – Elementary; grades PK-04. 160 LERAY ST, BLACK RIVER, NY 13612. 315-773-5911.
Brownville School – Elementary; grades 03-06. 771 MAIN ST, BROWNVILLE, NY 13615. 315-779-2300.
Antwerp Primary School – Elementary; grades PK-03. 6 ACADEMY ST, ANTWERP, NY 13608. 315-659-8386.
La Fargeville Central School – Other; grades PK-12. 20414 SUNRISE AVE, LA FARGEVILLE, NY 13656. 315-658-2241.
Lyme Central School – Other; grades PK-12. 11868 ACADEMY ST, CHAUMONT, NY 13622. 315-649-2417.
Hospitals
Local hospital contacts
Facility contacts from the CMS Hospital General Information directory, updated July 22, 2026. Contact the facility directly to confirm current services and appointment arrangements.
River Hospital Clinics – Critical Access Hospitals. 4 Fuller Street, Alexandria Bay, NY 13607. 315-482-2511.
Carthage Area Hospital, Inc – Critical Access Hospitals. 1001 West Street, Carthage, NY 13619. 315-493-1000.
Samaritan Medical Center – Acute Care Hospitals. 830 Washington Street, Watertown, NY 13601. 315-785-4000.
New York statewide resources
Public Safety
Use these official resources for law-enforcement information, criminal-justice services, safety programs and public-safety assistance.
- New York State Police — State Police services, safety information, news and contact resources.
- Division of Criminal Justice Services — Criminal-justice programs, public-safety resources, statistics and services.
- Sex Offender Registry — Search New York State public sex-offender registry information.
- Missing Persons Clearinghouse — Official missing-person information and resources.
- Office of Victim Services — Information about victim compensation, assistance programs and local service providers.
- Traffic Safety — Statewide traffic-safety programs, education and highway-safety information.
- Homeland Security & Emergency Services — Preparedness, emergency management, fire prevention and homeland-security programs.
- NY.gov Safety & Justice Services — Search state services related to safety, justice and identification.
New York statewide resources
Emergency Services
For life-threatening emergencies call 911. These resources help with statewide alerts, preparedness, road conditions, disasters and emergency information.
- NY-Alert — Sign up for emergency notifications and public-safety alerts.
- Division of Homeland Security and Emergency Services — Emergency management, disaster preparedness, fire prevention and response resources.
- Before an Emergency — Build an emergency plan, prepare supplies and learn how to stay informed.
- 511NY — Check traffic, transit, road closures, incidents and travel conditions.
- National Weather Service — Official weather forecasts, watches, warnings and severe-weather information.
- FEMA — Federal disaster preparedness, response and assistance resources.
- American Red Cross — New York — Disaster assistance, preparedness information, shelters and local services.
- New York State Police — State Police contacts and public-safety information.
New York statewide resources
State Parks
Plan a New York park trip with official park finders, camping tools, events, passes, historic sites and recreation information.
- Find a State Park — Search New York state parks by region, county and recreation options.
- New York State Parks — Main portal for parks, historic sites, recreation, events and visitor information.
- Camping — Camping information, policies and reservation guidance for state parks.
- Park Activities — Explore trails, boating, swimming, golf, birding and seasonal activities.
- Park Regions — Browse parks and recreation opportunities by New York State Parks region.
- Historic Sites — Explore state-operated historic sites, museums and heritage destinations.
- DEC Places to Go — Find state forests, wildlife areas, campgrounds and other DEC-managed lands.
- DEC Camping — Camping information for DEC campgrounds and backcountry areas.
New York statewide resources
Trails
Find hiking, biking and multi-use trails, maps, safety information and public-land recreation throughout New York.
- DEC Hiking — Hiking destinations, seasonal suggestions, trail guidance and Hike Smart NY safety information.
- New York State Parks Trails — Trail information for parks and historic-site properties.
- DECinfo Locator — Interactive map for trails, parking, campsites, lean-tos and state-managed lands.
- Empire State Trail — Official information for the statewide multi-use trail connecting major regions of New York.
- Accessible Recreation — Find accessible hiking, fishing, boating, camping and picnic locations.
- State Park Activities — Browse hiking, biking, snowmobiling and other outdoor recreation options.
- DEC Places to Go — Discover public lands and recreation areas across the state.
- Hike Smart NY — Safety, planning and preparedness information for New York hikers.
New York statewide resources
Utilities
Find consumer help for electric, gas, water, telephone and cable services, plus energy-assistance and utility-regulation information.
- Department of Public Service — Utility regulation, consumer information and Public Service Commission resources.
- File a Utility Complaint — Get help with regulated utility billing or service problems after contacting the provider.
- Ask PSC — Consumer information and answers about electric, gas, telephone, cable and water utility issues.
- Utility Consumer Assistance — Online consumer complaint and case-status system.
- Home Energy Assistance Program — HEAP information for eligible households needing help with heating and energy costs.
- NYSERDA — Energy-efficiency, clean-energy and consumer energy programs.
- New York State Broadband Program — State broadband information, mapping and connectivity programs.
- NY.gov Services — Search statewide housing, energy and utility-related services.
Libraries
Local library contacts
Locations and public phone numbers are from the IMLS FY2024 Public Libraries Survey. Call the branch to confirm current hours and services before visiting.
Adams Free Library – 2 North Main Street, Adams, NY 13605. 315-232-2265.
Adams Center Free Library – 18267 State Route 177, Adams Center, NY 13606. 315-583-5501.
Macsherry Library – 112 Walton Street, Alexandria Bay, NY 13607. 315-482-2241.
Crosby Public Library – 59 Main Street, Antwerp, NY 13608. 315-659-8564.
Belleville Philomathean Free Library – 8086 County Route 75, Belleville, NY 13611. 315-846-5103.
Sally Ploof Hunter Memorial Library – 101 Public Works Drive, Black River, NY 13612. 315-773-5163.
Brownville-Glen Park Library Association – 216 Brown Boulevard, Brownville, NY 13615. 315-788-7889.
New York statewide resources
Courts
Find courts, case information, forms, self-help guidance and court services through the New York State Unified Court System.
- New York Courts — Main portal for the New York State Unified Court System.
- Find a Court — Search courts by county, court type and case type.
- CourtHelp — Plain-language information for people handling common court matters.
- eCourts — Access public case information for supported New York court matters.
- Court Forms — Find statewide and court-specific forms.
- Programs & Services — Access ADR, accessibility, criminal-history search and other court-user services.
- Jury Service — Official New York juror information and service guidance.
- Law Libraries — Find court law libraries and legal-research assistance.
DMV
New York statewide resources
Transportation
Check traffic and transit conditions, travel information, state highways and transportation services before you go.
- New York State Department of Transportation — State highway, transportation program, project and safety information.
- 511NY — Live traffic, incidents, road conditions, transit and travel information.
- NYSDOT Travel Center — Travel tools, winter road conditions, transit information and trip-planning resources.
- 511NY TransLinks — Find public transportation, paratransit and travel links by region or county.
- New York State Thruway Authority — Thruway traffic, tolling, service areas and traveler information.
- MTA — Subway, bus, commuter rail and transit information for the New York metropolitan region.
- Amtrak New York — Intercity passenger rail information serving New York destinations.
- Travel Information, Advisories & Maps — State travel advisories, maps and road-information links.
Postal Services
USPS location finder — Search by street address, city or ZIP Code for nearby post offices, collection boxes and available services.
USPS ZIP Code lookup — Find the mailing ZIP Code for a specific street address.
USPS Hold Mail — Arrange a temporary mail hold and review identity-verification requirements.
USPS change of address and forwarding — Review forwarding options and submit an address-change request through USPS.
USPS package pickup — Check pickup availability for your address and schedule eligible shipments.
Veterans
National services available to local residents
VA accredited representatives — Find help with VA claims and benefit applications.
VA health care applications — Review application options and supporting information.
VA disability claims — Find the official steps for submitting a disability claim.
GI Bill and education benefits — Review how to apply for VA education benefits.
Veteran career and employment support — Explore VA employment, training and career assistance.
Employment
National services available to local residents
USAJOBS federal employment — Search federal openings by location and occupation.
Apprenticeship Finder — Search apprenticeship opportunities by location and occupation.
My Next Move career exploration — Explore occupations, industries and career interests.
Government job-training resources — Find routes to state training programs and support for different job seekers.
Unemployment benefit guidance — Find your state program and its application and eligibility information.
Get to Know Jefferson County
Useful answers for residents, visitors and anyone planning their next step.
Local Questions
Jefferson County Questions, Answered
Explore practical details about the county and the organizations that serve it.
111,540 (July 1, 2025 Census estimate). This is a dated Census Bureau estimate, rather than a live resident count.
1,857.357 square miles, including water (2020 Census geography). The total combines land and water area.
Start with these official New York resources: DMV Office Locations and Reservations; Renew a License; Registrations. Choose the page for the service you need, then check its office or online instructions before making a trip. These links cover state services; they do not establish that every transaction is available at a county office.
Use USPS ZIP Code Lookup for the mailing ZIP Code of a specific street address. Use the USPS location finder to search for nearby postal facilities and available services. An address lookup is more useful for mailing than assuming the entire county shares one ZIP Code.
The VA explains how to find and appoint an accredited representative for benefit claims. Contact a representative to confirm availability before appointing them. For education benefits, use the GI Bill application guidance. These are national VA services available to eligible local residents, rather than a listing of county offices.
Search USAJOBS for federal positions and the Apprenticeship Finder for apprenticeship opportunities, using location filters to narrow the results. USAGov job-training guidance points to training programs and state resources. Check each listing for current availability, eligibility and application instructions; a search result does not guarantee an opening in the county.
Jefferson County was established in 1805 from part of Oneida County and named for Thomas Jefferson. Watertown became the seat, with its public square forming an important civic reference. The city's history identifies an early paper mill in 1808, connecting the Black River's waterpower with industrial development. County resources also describe dairy agriculture as part of the wider regional story. These themes link the administrative center to both river-based manufacturing and the countryside beyond it.
Start with Watertown's public-square and river history, then use local resources to follow a more specific industrial or agricultural theme. The paper-mill story helps explain why the Black River mattered beyond scenery. Historic industrial locations should not be assumed open for a visit, so select current public destinations through their own information. A county-focused outing can connect the civic center with the working landscape rather than treating either as a complete picture on its own.
The 2020 Census geography figures record 1,268.704 square miles of land and 588.653 square miles of water in Jefferson County. The county’s total area includes both. These are geographic measurements for that Census vintage, not a measurement of current water levels or public recreation access.
In the Census Bureau’s 2025 estimate series, Jefferson County had an estimated 116,075 residents on July 1, 2020, and 111,540 on July 1, 2025. Over that interval, the estimated population decreased by 4,535 residents, or about 3.9%. Both figures come from the same estimate vintage, which revises earlier years for a consistent comparison.
Watertown is the county seat listed for Jefferson County by the National Association of Counties. For an office visit, confirm the specific department’s address before traveling. NACo county profile.
Shop - Dine - Discover
Meet Local Businesses
Support the businesses that help make our communities thrive. From family-owned shops and restaurants to trusted local services, discover businesses worth visiting throughout the county.
My Local Guide
Find Something Fun
Make Time to ExploreBrowse local places by the kind of day you have in mind.
A New Stop, a Local ConnectionExplore the Listings Below