Nymphs that resemble a number of different kinds of insect larvae and nymphs are probably the most practical. Such old standbys as the Muskrat Nymph and the Hare's Ear are well worth carrying, as are imitations of large stoneflies and dragonfly nymphs.

Attractors such as the Woolly Worm and its cousin the Woolly Bugger, Green Weenie and the [censored] Creek Nymph. These resemble a variety of aquatic critters.

A bugger resembles nothing in nature when it's perched in a vise, but when it is soaking wet and on the move, it truly comes alive. Depending on hook size and how it's weighted and retrieved, it can mimic a minnow, crayfish, leech or aquatic insect.

The Weenie, besides a flash of color, can mimic a catapillar or inchworm.

Every stream sampled usually contains at least a few green-bodied caddis, and in many rivers they are a trout's daily special.

The Green Rock Worm patterns actually represent a couple of so-called "free-living" caddis species. These larvae don't build portable houses for themselves but instead crawl among rocky crevices and clumps of vegetation on stream bottoms.

Dry flies such as Blue-Winged Olive in small size hooks ( 12-18 ) may be worth the while. They usually are a staple spring mayfly hatch and in the west sometimes in Winter.

Caddis hatch at sporadic times during the winter months on many waters, so it makes sense to carry a few Elk Hair Caddis, or something close to it.

Also, cold weather or winter plays well for what are called Streamers. Lethargic trout are less apt to go after nymphes (larvae) but being cannibalistic are more prone to strike small fish or crayfish which a streamer may represent.

Note: Dry flies are cast upstream and allowed to float downstream, while Wet Flies and/or Nymphes (larvae) are cast across or downstream with a small split-shot weight and drawn against the current for a swimming action.