Lake Arthur provides more than 42 miles of scenic shoreline. Its tributaries include:
- Muddy Creek
- Big Run
- Swamp Run
- Bear Run
- More than 75 intermittent streams
Ranging from an average depth of 11 feet to about 36 feet deep near the dam, the shallow waters of Lake Arthur are home to a variety of warmwater fish. Frogs, newts, turtles, and water snakes prowl the edges of the lake.
Great blue herons, green herons, and belted kingfishers prey on minnows and fish fry. During the early spring, common loons stop at the lake on their migration north.
Osprey may be seen flying over Lake Arthur. Once extirpated from Western Pennsylvania, these “fish hawks” have been reintroduced to Moraine through a hacking program begun during 1993.
The first osprey pair to nest along Lake Arthur as a result of this effort raised three young during 1996. Due to a successful reintroduction program statewide, the osprey population has recovered and is continuing to expand. Bald eagles also are actively nesting in the park.
A waterfowl observation deck is along Park Road.