Originally Posted by 2weightfavorite
I kind if like the negative outcome appeal that most everyone had posted on here....must be why the rivers are devoid of people in the winter. Trout are catchable regardless of how cold the water temps are. Not sure who started the under 40 theory...
If you type "trout's metabolism rate 40 degrees" or "trout's metabolism rate below 40 degrees" into Google, you will get a ton of hits on this topic including some good scientific data on metabolism, growth rates, and even feeding habits.
Fish being "catchable" is a broad description of the conditions. Fish are always catchable. Of course, you may need to resort to dynamite under some circumstances...
I've caught trout in water that looked like chocolate milk, so of course the fish were catchable, but I'm sure that most anglers didn't get as lucky as I did.
I'm with you in that I love to fish in the winter, largely because there are fewer people, and yes, I have had some amazing days in the winter. However, both a trout's metabolism and aquatic insect activity is closely tied to water temperature. Fewer bugs moving around in the water means less feeding opportunities for trout. Cold water means they are more lethargic and less likely to move much for a snack. While excellent anglers such as yourself can catch a good number of fish on cold days, the average person who fishes the Park when the water is under 40 will catch few if any trout and then wonder what they are doing wrong. The fact is, they aren't necessarily doing anything wrong but unless you fish the streams on a regular basis and are intimately familiar with deep nymphing techniques, catching fish is going to be tough.
That said, some of the largest fish caught in the Park have been caught in the cold months (January and February) when the water is under 40. So again, can you catch fish? Certainly. Can you even catch a lot of fish? Yep. Just don't expect it every trip.