Went out for a final day of fishing before the season closed at cottage lake. When I got to the lake I saw a man leaving with a stringer full of trout around 15''. I fished for 3 hours and wasn't able to land anything but the people next to me kept bringing' em in. Finally figured out that the reason they were catching so many was the spot they were fishing in next to the sinkhole. I gave a cast into it and instantly got a huge hit with a rooster tail. As I reeled it into the dock I saw an ugly dark green/brown fish emerge. I tried to pick it up but it broke the line with it's weight. I'm still trying to figure out what in the HELL it was. With my only guess of it being a brown bullhead or maybe a carp or even possibly a sick old smallmouth bass.