Southwest of Oil City, the Clarion River is popular for fly fishing. The popular section for fly fishing on the Clarion River is from Ridgway down to the town of Clarion. The best section on the Clarion River for fly fishing is considered to be the catch and release zone from Johnsonburg to Ridgeway that is filled with brown trout. This latter section does not have any public access, so make sure to get a private landowner permission before accessing.
Overall, Clarion River is the 13th most popular fly fishing river of all 49 fly fishing spots in Pennsylvania.