Yes, at one time the Clarion River was very bad for fishing. My grandfather said that there used to be a tannery up in Johnsonburg when he was a kid and all that you would ever catch was possibly a carp or catfish. He didn't catch his first bass in it until he was a senior in high school, and it wasn't from a lack of fishing. He said that he would walk from his house on Miola road and follow the Callihan Run to the Clarion River. He says that you would wade in and the water was so dirty that you couldn't see your feet. Now, the Clarion River is easily one of the nicest fisheries in the area. I have caught bass, trout of all species, catfish and walleye. I particularly love the section from Gravel Lick bridge to Sarvey Mill Road. You can only do this section by boat, but it is never a disappointment.
I work on cookforest state park. Which the clarion river run through. I consider clarion river to be a secret river for smallmouths. At one time, i was told that everything in the river was almost died off at one time. But i have been fishing the river for over 10 years and i found that the river is doing alot better. In the summer i like to use jitterbugs and rubber lizards. And this time of year i use jigs or live shiners. I catch more in the summer but bigger smallmouths in the winter into early spring. My average this time of year is around 15''-18''.
Very good smallmouth fishing
The Clarion River is a tributary of the Allegheny River, approximately 110 mi (177 km) long, in west central Pennsylvania in the United States. It drains a mountainous area of the Allegheny Plateau in the Ohio River watershed, flowing through narrow serpentine valleys and hardwood forests.