Largest Lakes in Pennsylvania
2 Pennsylvania lakes with measured surface area, ranked by acreage. The biggest lake in Pennsylvania is Lake Nockamixon, which tops the list at 1,450 acres in Bucks County.
Reading Pennsylvania's size profile
Pennsylvania's largest lake by surface area is Lake Nockamixon in Bucks County, spanning 1,450 acres. Most of Pennsylvania's biggest waters are reservoirs — dammed river valleys built for water supply, flood control, and recreation, so their footprints shift with pool level.
Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.
The 2 biggest lakes in Pennsylvania by surface area
| # | Lake | County | Surface area | Max depth | Grade |
|---|---|---|---|---|---|
| 1 | Lake Nockamixon | Bucks | 1,450 acres | - | D |
| 2 | Lake Carey | Wyoming | 263 acres | - | D |
Frequently Asked Questions
What is the largest lake in Pennsylvania?
The largest lake in Pennsylvania in the LakeGrade dataset is Lake Nockamixon in Bucks County at 1,450 acres. Water quality grade: D.
How is lake surface area measured?
Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.
Are Pennsylvania's largest lakes natural or reservoirs?
Of the top 2 Pennsylvania lakes by area, 2 sit on a dammed river (reservoirs) and 0 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.
Do larger lakes have better water quality?
Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one grade can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.
How big is the typical Pennsylvania lake in this ranking?
Across the top 2 Pennsylvania lakes by surface area, the median is 263 acres (Lake Carey). This list is biased toward the biggest waters; the typical Pennsylvania lake is far smaller.
Where to stay near Pennsylvania's largest lakes
Planning a trip? Jump to live cabin, resort, and hotel availability near Pennsylvania's biggest lakes.