Keystone Lake comprises 850 acres stretching 5.5 miles and is the largest lake in Armstrong County. The lake contains shallows and wetlands, and gets as deep as 90 feet.
Owned and operated by Reliant Energy as a cooling water supply for Keystone Power Plant, the lake and surrounding area is open for public use and is controlled by the PA Fish & Boat Commission and all their rules and regulations. No swimming is allowed in the lake, but boats up to 9.9 horse power are allowed.
Keystone Lake provides an excellent warm water fishery with large and small mouth Bass, Walleye, Musky, Perch, Crappies, Bluegills, Sunfish, Pumpkin Heads, and Trout (stocked). A Trophy Bass Lake, professional tournaments have been held here.
The Lake has two formal boat launches at NuMine (north shore) – off of Route 85 at White Oak Road, and Atwood (south shore) – off of Route 210 at the village of Atwood. These are excellent facilities with large parking areas. There are also several primitive access areas around the lake.
Several thousand acres surrounding the lake are open to hunting (PA Game Commission laws and regulations apply). If winter weather conditions permit, Keystone Lake is an excellent place for ice fishing!