Two canoes crossing open water between forested points in the Boundary Waters

Updated August 2026

Biggest Lake in Pennsylvania: Raystown Lake (8,300 acres)

Raystown Lake is Pennsylvania's largest inland lake per the PA Fish & Boat Commission (biologist report); USACE Baltimore District. Below: 50 Pennsylvania lakes ranked by surface area.

The largest lake in Pennsylvania is Raystown Lake at 8,300 acres , in Huntingdon and Bedford County, according to the PA Fish & Boat Commission (biologist report); USACE Baltimore District. PA DCNR states 'The 17,088-acre Pymatuning Reservoir is the largest lake in the Commonwealth' (https://www.pa.gov/agencies/dcnr/recreation/where-to-go/state-parks/find-a-park/pymatuning-state-park), but Pymatuning straddles the Pennsylvania-Ohio line and is co-managed with Ohio (either state's fishing license is honored on the water). Lake Erie's Pennsylvania waters are larger still, but Erie is a shared Great Lake. Raystown is therefore the largest lake entirely inside PA.

See our Raystown Lake water-quality report card NR

Source: PA Fish & Boat Commission (biologist report); USACE Baltimore District (2026-07-30). The table below ranks the Pennsylvania lakes in our own index by surface area.

Lakes with area data

13,926

Largest (acres)

586

Median of top 50

1/50

Reservoirs (vs natural)

Reading Pennsylvania's size profile

Pennsylvania's largest lake by surface area is Pymatuning Reservoir in Crawford County, spanning 13,926 acres. Most of Pennsylvania's biggest waters are natural basins left by glaciers, with stable shorelines and deep main basins.

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 50 biggest lakes in Pennsylvania by surface area

#	Lake	County	Surface area	Max depth	Grade
1	Pymatuning Reservoir	Crawford	13,926 acres	-	NR
2	Allegheny Reservoir	Warren	12,222 acres	-	NR
3	Raystown Lake	Huntingdon	8,136 acres	-	NR
4	Shenango River Lake	Mercer	3,485 acres	-	NR
5	Lake Arthur	Butler	3,075 acres	-	NR
6	Foster Joseph Sayers Lake	Centre	1,676 acres	-	NR
7	Glendale Lake	Cambria	1,585 acres	-	NR
8	Lake Wilhelm	Mercer	1,567 acres	-	NR
9	Lake Nockamixon	Bucks	1,450 acres	-	NR
10	Van Sciver Lake	Bucks	1,397 acres	-	NR
11	Blue Marsh Lake	Berks	1,178 acres	-	NR
12	Lake Marburg	York	1,173 acres	-	NR
13	East Branch Clarion River Lake	Elk	1,111 acres	-	NR
14	Cowanesque Lake	Tioga	1,079 acres	-	NR
15	Beltzville Lake	Carbon	1,044 acres	-	NR
16	Ontelaunee Lake	Berks	1,019 acres	-	NR
17	Beaver Run Reservoir	Westmoreland	1,006 acres	-	NR
18	Conneaut Lake	Crawford	951 acres	-	NR
19	Quemahoning Reservoir	Somerset	877 acres	-	NR
20	Curwensville Lake	Clearfield	874 acres	-	NR
21	Keystone Lake	Armstrong	865 acres	-	NR
22	Green Lane Reservoir	Montgomery	779 acres	-	NR
23	Harveys Lake	Luzerne	629 acres	-	NR
24	DeHart Reservoir	Dauphin	596 acres	-	NR
25	Shohola Marsh Reservoir	Pike	595 acres	-	NR
26	Mahoning Creek Lake	Indiana	586 acres	-	NR
27	Pocono Lake	Monroe	526 acres	-	NR
28	Tionesta Lake	Forest	524 acres	-	NR
29	Crooked Creek Lake	Armstrong	518 acres	-	NR
30	Marsh Creek Reservoir	Chester	500 acres	-	NR
31	Indian Lake	Somerset	497 acres	-	NR
32	Crystal Lake	Luzerne	490 acres	-	NR
33	Promised Land Lake	Pike	468 acres	-	NR
34	Penn Forest Reservoir	Monroe	464 acres	-	NR
35	Two Lick Creek Reservoir	Indiana	455 acres	-	NR
36	Shawnee Lake	Bedford	445 acres	-	NR
37	Manor Lake	Bucks	441 acres	-	NR
38	Pecks Pond	Pike	411 acres	-	NR
39	Ambridge Reservoir	Beaver	406 acres	-	NR
40	Huntsville Reservoir	Luzerne	402 acres	-	NR
41	Pikes Creek Reservoir	Luzerne	398 acres	-	NR
42	Hall Pond	Lycoming	383 acres	-	NR
43	Middle Creek Reservoir	Lancaster	369 acres	-	NR
44	Springton Reservoir	Delaware	364 acres	-	NR
45	Mauch Chunk Lake	Carbon	361 acres	-	NR
46	Peace Valley Reservoir	Bucks	359 acres	-	NR
47	Pinchot Lake	York	358 acres	-	NR
48	Still Creek Reservoir	Schuylkill	338 acres	-	NR
49	Stillwater Lake	Monroe	320 acres	-	NR
50	Woodcock Creek Lake	Crawford	317 acres	-	NR

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Frequently Asked Questions

What is the largest lake in Pennsylvania?

Raystown Lake, at 8,300 acres, in Huntingdon and Bedford County. PA DCNR states 'The 17,088-acre Pymatuning Reservoir is the largest lake in the Commonwealth' (https://www.pa.gov/agencies/dcnr/recreation/where-to-go/state-parks/find-a-park/pymatuning-state-park), but Pymatuning straddles the Pennsylvania-Ohio line and is co-managed with Ohio (either state's fishing license is honored on the water). Lake Erie's Pennsylvania waters are larger still, but Erie is a shared Great Lake. Raystown is therefore the largest lake entirely inside PA. Source: PA Fish & Boat Commission (biologist report); USACE Baltimore District, 2026-07-30.

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 50 Pennsylvania lakes by area, 1 sit on a dammed river (reservoirs) and 49 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 50 Pennsylvania lakes by surface area, the median is 586 acres (Mahoning Creek Lake). 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.

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