Keystone Lake
Armstrong County, Pennsylvania865 acresView mapDirections
PA DEP publishes the water-quality measurements for Keystone Lake. Here is what has been measured.
- 90 ft max depth
- Public access
- Limited data
Keystone Lake in Armstrong County, Pennsylvania has water-quality measurements published by PA DEP, shown here as reported. Phosphorus: 12.5 µg/L. Chlorophyll-a (algae): 13.6 µg/L. Maximum depth: 90 ft. Surface area: 865 acres.
Keystone Lake is a 865-acre lake in Armstrong County, Pennsylvania with a maximum depth of 90 feet. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, PA DEP, last sampled 2021-12-02. Methodology: how these readings are compared.
What Keystone Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Deep water90 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Keystone Lake is safe to swim in today is a call for the Pennsylvania Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Keystone Lake
These are the measurements PA DEP publishes for Keystone Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 12.5 µg/L. Chlorophyll-a 13.6 µg/L.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 12.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 13.6µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
Ask about Keystone Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
90 ft
Surface area
865 acres
Shoreline
15.5 mi
Public access
Yes
Listed by PA DEP
Recreation & Access
- AtwoodPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Keystone Lake
Compare lakeside cabins, hotels, and vacation rentals near Keystone Lake in Armstrong County, Pennsylvania — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Keystone Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Keystone Lake → · more Pennsylvania lake trips
Follow Keystone Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Keystone Lake
Nearby Lakes in Armstrong County
Frequently asked questions about Keystone Lake
Where is Keystone Lake?
- Keystone Lake is a lake in Armstrong County, Pennsylvania. Its water-quality measurements are published by PA DEP and shown on this page as reported.
What is the water quality of Keystone Lake?
- Keystone Lake in Armstrong County, Pennsylvania has water-quality measurements published by PA DEP, shown here as reported. Phosphorus: 12.5 µg/L. Chlorophyll-a (algae): 13.6 µg/L. Maximum depth: 90 ft. Surface area: 865 acres.
Is Keystone Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Keystone Lake?
- Keystone Lake has a maximum depth of 90 feet. The lake covers 865 acres.
Are there boat ramps on Keystone Lake?
- Keystone Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Atwood. Public access is listed as yes.
Can I fish at Keystone Lake?
- Keystone Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Pennsylvania's fish and wildlife agency, so check its current regulations before you go.
Explore Keystone Lake across LakeQuality
More lakes in Pennsylvania
Other Lakes in Pennsylvania
Compare Keystone Lake With Nearby Lakes
Where this data comes from
Measurements for Keystone Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Named boat-access points from the USGS National Boat Ramps inventory