- Aylen Lake is located northwest of Barry's Bay and just south of the Algonquin Park boundary in the District of Nipissing
- There are at least 11 streams flowing into the lake. The Aylen River flows in on the north end and exits via a dam on the southwest end
- Aylen is a typical Canadian Shield lake with deep clear cold water that is well oxygenated and favours a cool to cold water fishery
- The lake reaches depths of 239', the average depth is 89'
- The perimeter of the lake is 46 km (29 miles)
- The Aylen River contains both small-mouth bass and brook troutA public boat launch is located by following Aylen Lake Road to the dam on the southwest side of the lakeThe major fish species include lake trout, small-mouth bass, whitefish and perch
- Aylen Lake is located within Fisheries Management Zone 15
Lake trout are recognized by their forked tail, long head and an abundance of spots. They are one of Algonquin Park's most sought after sport-fish. Lakers are found near the surface in spring and will take spoons and spinners, especially on the troll. As the waters warm, trolling deeper is necessary. Lead core or steel line is a popular method of finding where they are holding. Popular lake trout lures include the Williams Wobbler, Apex and Little Cleo. Note that only one line may be used when angling through the ice and there is a slot for Lake trout : none between 40-55 cm (15.7-21.7 in.).
Aylen Lake small-mouth bass have a reputation of putting up a great fight when hooked. They love structure and will gravitate to underwater drop offs and rocky shoals or shorelines. Recognized by their football shape and green bodies, underwater presentations are usually more effective for small-mouth bass. Popular choices used to catch small--mouth are the crayfish fly or lure, Berkley jigs, Mepps or Blue Fox spinners.