The Kenai River is a meltwater river that drains the central Kenai Peninsula region. Its source is the Kenai Lake. Near Cooper Landing, the lake narrows to form the river. About from the lake, the river passes through Kenai Canyon for about of fast-flowing whitewater rapids. The Russian River empties into the Kenai several miles west of Cooper Landing. from Kenai Lake, the river enters Skilak Lake. The Kenai Lake to Skilak section is commonly referred to as the "Upper River". The portion from Skilak Lake downstream to the Sterling Highway bridge near Soldotna is known as "Middle River". The final from the bridge to the mouth at Cook Inlet is known as the "Lower River", where the flow is much gentler. The final are greatly influenced by changing tides.
Fish
The Kenai River is the most popular sport fishing destination in Alaska, particularly for king salmon. Each year there are two runs each of king salmon, coho salmon, sockeye salmon, plus a run of pink salmon every other year. The world record king salmon, which weighed about 44 kg, was caught in the Kenai River in 1985. The Kenai is also the home of trophy sizerainbow trout and Dolly Varden. Stretching to sizes over 76.2 cm. Occasionally there will be reports of catching of "Steelhead". The king salmon fishery is not as prolific as in other Alaskan rivers, but the Kenai is known for its large fish. A typical king in the second run, beginning in mid-July, weighs 40–85 pounds, with considerably larger specimens not uncommon. The "Lower Kenai" is well known for its run and sizes of its king salmon. In recent years, the king salmon fishery has been closed or heavily restricted due to low returns of fish. The coho salmon runs occur in early August and early October. The September run is favored by local anglers due to the larger size of the silver salmon. The sockeye salmon runs are in late-June and early-August. Sockeyes are considered the premier salmon for eating, canning, and smoking. The pink salmon run occurs in even numbered years only. These fish are considered pests by many anglers because they interfere with catching other species and because, by the time they reach inland freshwater, their meat may be soft and oily compared to other species. On a heavy day, even a casual fisher might catch several dozen of the species.
Other wildlife
Along with Kenai's fish, the Kenai River area is home to other wildlife, including moose, bears, and multiple species of birds.
Management
Over of the river and lakes are managed by the Alaska Department of Natural Resources as the Kenai River Special Management Area, from inland of the river mouth at Cook Inlet, to upstream. Adjacent to the management district are fifteen different parks.