I waded up to my knees in the lake and tied on a diminutive No. 18 Griffith's Gnat, a classic "cluster midge" fly. My line was a 5-weight, and my leader was tapered down to a 6X.

I cast out over the edge of the dropoff and let the fly sit on the surface.

It took me quite a while. I fan-cast around the clock. There was just a whisper of a breeze, and I let it work the fly gently over the edge of the dropoff.

But nothing happened.

If I hadn't seen the trout before, at Thanksgiving, I'm sure I would have quit. But it was a nice day for January, and for at least an hour, I must have kept casting and slowly working the fly back to me.

Then I saw a dimpling rise to my left. Moments later, there was another on my right side.

I was tempted to pick up my rig and cast to one of the rises. But some sensible part of me left the fly alone, working on the surface with the breeze.

Suddenly, I felt a soft pull. It was hardly noticeable, but I as raised up the rod, I felt a solid resistance.

And then the surface erupted.

It was a nice fat rainbow -- a hatchery fish that had escaped the summer anglers. It jumped three times and fought hard. It was about 12 inches long, with a vivid pink stripe, lavender cheeks and silver sides.

I eased the hook from its mouth, cradled it briefly in the cold water, and then it swam away.

I probably fished longer for that trout than any other fish that year. I also remember it better than many larger, easier fish. (Continued)

GETTING TO KNOW CHIRONOMIDS
Midges -- the common name for the family of small insects more accurately referred to as chironomids -- are almost always the last insects a novice flyfisherman tries to imitate.

The vast majority of midges are small, rarely more than an 1/8 of an inch as adults. Many new flyfishers feel intimidated at the prospect of fishing flies tied to imitate such a small insect.

They also find it hard to believe that good-sized trout can be landed on a fly tied on a hook as small as size 20 or 22.

Other anglers doubt that decent-sized trout will pay much attention to such tiny food items. For anglers older than 40 years of age, it can be frustrating to even thread the tippet through the hook eye on such a small fly.

Well, let me set the record straight. Trout -- including some very large trout -- do indeed feed on midges.

Research on Colorado's South Platte River during winter found 300 midges for every mayfly in trout's stomachs.

In mountain lakes, midges are such an important food source that some biologists believe trout couldn't survive without them. Flies tied to imitate these chironomids will catch all sizes of trout. Anglers who play the fish carefully can land very large trout on midge patterns.