"Big Bear does allow the use of some larger flies like a bead-head Wooly Bugger in small sizes," Kern said. "These mostly imitate baitfish, rather than insects. Again, darker colors -- mostly black. Occasionally, olive or dark brown.

"I will fish sections of the lake that I know from experience hold most of the trout. You also have to cover lots of water to find those spots where the fish are stacked up."

Big Bear is not a deep lake, and trout exhibit seasonal movements depending on water temperature and oxygen levels. When surface temps get really low, the trout will school in the deepest spots they can find that have sufficient oxygen. Even a shallow depression in the bottom will often hold a large number of trout. If you can find these, you should be able to catch them in most other Western lakes and reservoirs that don't have extreme depth.

Kern also suggested another bottom feature that often gets overlooked.

"Natural springs that flow under the surface of the lake are a good bet any time of year," Kern noted.

"In the winter, they are often slightly warmer than the surrounding waters. And in the summer, they are always cooler. The water there is always well oxygenated. These are major trout attractors."

Rivers in winter are always well oxygenated, so that isn't a problem. Here temperature plays a bigger role, and the fly anglers venturing onto a cold January river need to be thorough with their presentation, working all the water that could potentially hold trout. Kern River Troutfitters Fly Shop owner and guide Guy Jeans of Kernville, Calif., fishes extensively on the Kern River drainage from the Golden Trout Wilderness all the way down to Bakersfield.

The Kern is a big river and is split in two by massive Lake Isabella. Much of the fishing in spring and summer takes place above Isabella. But in winter, the best trout angling is often on the lower Kern.

"In the winter, we fish below Lake Isabella. The flows are better than above the lake, and it's somewhat warmer," Jeans said. "We fish a lot with a three-nymph rig called the Czech Rig that was developed in the Czech Republic. It uses a leader about the same length as your rod, usually around 9 feet. Then you have a triple Surgeon's Knot with a short dropper, then go down about 18 inches for the second fly, and add a third nymph on the bottom.

"Typically the Czech rig is used with weighted flies, but I often use a few tiny split shot between the bottom fly and the middle to get the flies down in the current.

"I tried out for the United States Fly-Fishing trials and saw it there. It increases your strike rates by 50 percent. I will put on the Kern Emerger, basically a Hare's Ear with different colored wing cases on it, and often use three different colors of the Emerger. Sizes can vary tremendously, anywhere from a size 8 to size 18. I vary the weights and sizes to get what the fish want."

Now three-fly rigs, known as a "cast" of flies, are nothing new. For decades, some expert trout anglers have been fishing such setups, either with nymphs or wet flies of various kinds. These somewhat clumsy-looking rigs can be a killer when conditions are right.