Union County is a county in Pennsylvania, United States, in the Susquehanna Valley along the West Branch Susquehanna River. It had a population of 42,681 at the 2020 census and covers 318 square miles (820 km2), centred near 40°58′N 77°04′W.
Lewisburg is the county seat; its postal code is 17837. The county has 4 boroughs, 10 townships and a handful of unincorporated communities. Union County sits in the Eastern time zone and carries FIPS code 42119.
Towns & Villages in Union County
Union County’s settled places split into 4 incorporated boroughs and a longer list of unincorporated hamlets and crossroads spread across its 10 townships. Census-designated places (CDPs) are marked below; the rest are unincorporated communities with no municipal government of their own.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Lewisburg | Borough · seat | — | 5,792 | 17837 |
| Mifflinburg | Borough | — | 3,540 | 17844 |
| New Berlin | Borough | Limestone Township | — | 17855 |
| Hartleton | Borough | Union Township | — | 17829 |
| Linntown | CDP | East Buffalo Township | 1,489 | 17837 |
| Winfield | Unincorp. | Buffalo Township | — | 17889 |
| New Columbia | Unincorp. | White Deer Township | — | 17856 |
| Allenwood | Unincorp. | White Deer Township | — | 17810 |
| White Deer | Unincorp. | White Deer Township | — | 17887 |
| Millmont | Unincorp. | Hartley Township | — | 17845 |
| Laurelton | Unincorp. | Hartley Township | — | 17835 |
| Glen Iron | Unincorp. | Hartley Township | — | — |
| Weikert | Unincorp. | Hartley Township | — | — |
| Vicksburg | Unincorp. | Buffalo Township | — | — |
| Mazeppa | Unincorp. | Buffalo Township | — | — |
| Buffalo Crossroads | Unincorp. | Buffalo Township | — | — |
| Cowan | Unincorp. | Buffalo Township | — | — |
| Dry Valley Crossroads | Unincorp. | Buffalo Township | — | — |
| Kelly Crossroads | Unincorp. | Kelly Township | — | — |
| Kelly Point | Unincorp. | Kelly Township | — | — |
| Swengel | Unincorp. | Kelly Township | — | — |
| Fairville | Unincorp. | Kelly Township | — | — |
| Cherry Run | Unincorp. | Lewis Township | — | — |
| Forest Hill | Unincorp. | Lewis Township | — | — |
| Pleasant Grove | Unincorp. | Union Township | — | — |
| White Springs | Unincorp. | Union Township | — | — |
| Rand | Unincorp. | Union Township | — | — |
| Central Oak Heights | Unincorp. | West Buffalo Township | — | — |
| Tannertown | Unincorp. | West Buffalo Township | — | — |
| Red Bank | Unincorp. | West Buffalo Township | — | — |
| Lochiel | Unincorp. | East Buffalo Township | — | — |
| College Park | Unincorp. | East Buffalo Township | — | — |
| Turtleville | Unincorp. | — | — | — |
| Camp Hironimus | Unincorp. | White Deer Township | — | — |
| Old Furnace | Unincorp. | — | — | — |
| Pardee | Unincorp. | — | — | — |
| Spring Garden | Unincorp. | — | — | — |
| Wildwood | Unincorp. | — | — | — |
| West Lawn | Unincorp. | — | — | — |
| Johnstown | Unincorp. | — | — | — |
| Bucknell | Unincorp. (campus locale) | East Buffalo Township | — | 17837 |
West Milton, a small borough just east of the county line, sits mostly in neighboring Northumberland County; only its western fringe touches Union County, so it is not counted among Union County’s four boroughs above.
Townships
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| East Buffalo | — | Linntown, Bucknell University, Lochiel, College Park |
| Buffalo | — | Winfield, Mazeppa, Vicksburg, Buffalo Crossroads, Cowan |
| White Deer | — | Allenwood, New Columbia, White Deer |
| West Buffalo | — | Central Oak Heights, Tannertown, Red Bank |
| Limestone | — | New Berlin (borough) |
| Hartley | — | Millmont, Laurelton, Glen Iron, Weikert |
| Union | — | Hartleton (borough), Pleasant Grove, White Springs |
| Kelly | — | Kelly Crossroads, Kelly Point, Swengel, Fairville |
| Lewis | — | Cherry Run, Forest Hill |
| Gregg | — | Rural crossroads north of Mifflinburg |
Township-level 2020 census population figures were not verifiable at time of writing and are omitted rather than guessed.
ZIP Codes
- 17837 — Lewisburg (also serves Linntown and the Bucknell University campus)
- 17844 — Mifflinburg
- 17855 — New Berlin
- 17829 — Hartleton
- 17889 — Winfield
- 17856 — New Columbia
- 17887 — White Deer
- 17810 — Allenwood
- 17845 — Millmont
- 17835 — Laurelton
Smaller unincorporated places such as Mazeppa, Vicksburg, Kelly Point and Cherry Run share the ZIP code of their nearest post-office town rather than carrying one of their own.
Geography
Union County lies in the ridge-and-valley section of central Pennsylvania, split by the West Branch Susquehanna River, which forms much of its eastern edge. Bald Eagle State Forest covers a large share of the county’s western and southern townships, rising toward Jacks Mountain and Paddy Mountain; the lower Buffalo Valley in the county’s east and center holds most of its farmland and towns. The county borders Lycoming County to the north, Northumberland County to the east, Snyder County to the south, Mifflin County to the southwest, Centre County to the west and Clinton County to the northwest. No live townsvillages.com page was found for Northumberland County, Pennsylvania (the bare slug redirects to the Virginia county of the same name), so it is named here without a link.
Demographics
Union County’s 2020 census population was 42,681. Its two largest communities, Lewisburg and Mifflinburg, had 5,792 and 3,540 residents respectively as of the 2010 census, the most recent year with borough-level detail available at time of writing; Linntown CDP, just outside Lewisburg, had 1,489. The county’s median household income runs close to the Pennsylvania median of $73,824, lifted in part by Bucknell University employment in East Buffalo Township. Population density works out to roughly 135 people per square mile countywide, concentrated around Lewisburg-Mifflinburg and much thinner across the forested western townships.
Economy & Local Life
Bucknell University, based in Lewisburg, is the county’s largest employer and shapes much of its economy, from student housing to campus-adjacent retail. Evangelical Community Hospital, headquartered near Winfield, is another major employer and the region’s principal health system. Agriculture remains significant in the Buffalo Valley and around Mifflinburg, historically known for its buggy-making trade; Union County still holds an annual Community Fair and county-wide farm shows tied to that agricultural base. The Bald Eagle State Forest supports hunting, fishing and outdoor recreation across the county’s western half.
History
Union County was formed on March 22, 1813, from part of Northumberland County; its name is an allusion to the federal Union. Mifflinburg served as the first county seat under the organizing legislation, before the seat moved to New Berlin in 1815. Lewisburg was designated county seat in 1855 and has held that role ever since. Bucknell University, founded in Lewisburg in 1846 as the University at Lewisburg, has anchored the county’s largest town for more than 170 years.
Getting There
Interstate 80 crosses the northern part of the county, and US Route 15 runs north-south through Lewisburg and Winfield, connecting to Williamsport and Harrisburg.
- Williamsport — 25 miles north
- Harrisburg — 55 miles south
- State College — 40 miles west
- Sunbury — 12 miles east
The nearest commercial airport is Williamsport Regional Airport, about 30 miles north of Lewisburg.
Frequently Asked Questions
Where is Union County, Pennsylvania?
It sits in the Susquehanna Valley of central Pennsylvania, along the West Branch Susquehanna River, between Lycoming and Snyder counties.
What is the population of Union County?
Union County had a population of 42,681 at the 2020 census.
How big is Union County?
The county covers 318 square miles (820 km2), of which about 1.8 square miles is water.
What is the county seat of Union County?
Lewisburg is the county seat and has been since 1855.
How many towns are in Union County?
Union County has 4 boroughs (Lewisburg, Mifflinburg, New Berlin and Hartleton) plus 10 townships and roughly three dozen smaller unincorporated communities.
What ZIP codes are in Union County?
Major ZIP codes include 17837 (Lewisburg), 17844 (Mifflinburg), 17855 (New Berlin) and 17829 (Hartleton), among others listed above.
What is Union County known for?
It is best known as the home of Bucknell University in Lewisburg and for the Buffalo Valley farm country around Mifflinburg, once a center of horse-drawn buggy manufacturing.
More counties in this state: Towns and villages in Pennsylvania.