The relative abundance and large size of trout in western waters is largely accounted for in the abundance of both land and water insects. The winds blow meaty winged food from the hills and wide-open spaces into the water. These heavy insects account too for an occasional unwariness in western trout; it is more difficult for them to make a fine calculation regarding the plop of a grasshopper than the delicate egg-dipping of the May fly.
This is a matter of some significance for the understanding of western fly fishing. The variety of insects there has brought about the use of a wider variety of trout flies than is found in the East, including some garish specimens. From this has come the notion that western fly fishing is occupied not only with wild trout but with crude methods. There is some truth in this notion, but it has' grown into a myth and it conceals a fallacy regarding the nature of fly fishing.
Most of the best-known artificial trout flies were originated in England and (much later) on the eastern seaboard of the U.S., where the May fly predominates. The central position of this fly in the sport has made it the model of most trout flies since the 15th Century in recorded history. In the New World, new colors were found in the May fly, and in the late 19th Century we got the American flies, Quill Gordons, Cahills, Hendricksons and the like (along with a tendency to name flies for their designers).
Farther west, in Montana and Wyoming, not so long ago, fly fishermen discovered the grasshopper. There have always been other flies besides the May fly, but this one gave rise to a misunderstanding. Not being traditionalists any more than was the first fly fisher, western anglers made a new fly. This was the Hopper, or "Joe's Hopper," not bad looking but no May fly. It could be fished wet or dry and was found to be a killer on western rivers. They also made a "Woolly Worm" in various colors, probably the lowest in the order of artificial flies with its simple caterpillar body. These two flies probably lead in popularity among western patterns in the region of the park. The sight of them has led the provincial easterner to suspect the worst of western fly fishing; and he could not be more wrong on two counts.
On the first he is wrong in principle to confuse the beauty of the May fly with a rule of the game. Now the Hopper is a fur-and-feather fly, and fishing it is fly fishing. Fishing it is using a fly of the region, as fly fishers have always done. Furthermore, esthetically, the Hopper has a visual appropriateness in the heavy waters. It marks the region, not the game.
On the second count he is wrong in fact to believe that all or most of western fly fishing is done or can be done with flies modeled on grasshoppers. The experienced fishermen in the West simply use a wider variety of flies than the easterner, extending from the Hopper, Size 8, to a Quill Gordon, Size 18 (the size of a mosquito), on a 14-foot leader tapered to 6X, which is so fine that many fishermen use a magnifying glass as an aid to knotting a fly to it. On some of the creeks fed by springs and flowing as silkily as an English chalk stream, the trout will not touch anything under a Number 14.
The newcomer to the West would have cocked his eyebrows last September at fishermen floating Light Cahills and Adamses and some beautiful western May fly creations in these small sizes down big rivers such as the Big Hole and Yellowstone. The trout, including the biggest of them, disdained anything else throughout the season. No, there is no distinction in subtlety between these waters and the best waters of the East; there are only more kinds of fishing and more conditions?all the old problems and some new ones.
The seasons for western trout are determined by the run-off of snow water, and of course by regulation. The law prohibits early spring fishing in most streams and rivers. Nature limits the fishing, especially fly fishing, from the middle of June to the middle of August with relatively high and murky water. Up in the plateaus of the park, however, the water is good early, and fishing on most of the waters begins on Memorial Day. As the season proceeds the easily accessible park waters?those along the road?become less good, perhaps because of excessive fishing, while the waters downstream and out of the park get better as their level falls. The great season for the great rivers is from the middle of August to the first of October.
The fly fisherman can suit his taste by choice of river. For example, the most prized stream in the park is the Firehole. It originates in the geyser country around Old Faithful and glides north along the west side of the park, drops over falls and joins the Gibbon coming down from the north to form the upper Madison.
Taking its time through a slightly graded plateau, the Firehole makes a smooth run that causes it to be a favorite of the dry fly fishermen. The same might be said of the upper Madison, winding westward through woods and meadows to Hegben Lake just outside of the park. The Madison here flows slick and bears no resemblance to its turbulent waters below the lake. It is water for the long leader and the small fly, and is best in early season.