The trout stream and the earthquake
Two years agothis month, when an earthquake of major magnitude convulsed an area of 600,000square miles in northwestern America, fly-fishermen the world over shuddered.Had the Montana-Yellowstone quake of August 1959 done irreparable damage to oneof the world's most magnificent trout streams, the classic Madison River, andto other nearby streams, like the Gallatin?
The Madison,rising in Yellowstone National Park where the Gibbon and Firehole riverscombine to form its headwaters, flows some 140 delightful, fish-laden miles toThree Forks, where it joins the Gallatin and the Jefferson to start theMissouri River. Except for three lakes in its path and some few brief ruggedstretches like Bear Trap Canyon, almost every one of these miles can be wadedand is pocked with holes in which lie brown trout and rainbows, somecutthroats, an occasional brook trout and Montana grayling and white-fish. Thestream ripples swift, wide and cool over mossy stones, through deep gorges andacross broad, flat, flowery plains from which rise, snowcapped and splendid,the ochre mountains of the Madison Range.
In this streamfly casting was a carefree delight, for almost every fruitful spot could bereached without fear of hanging up on the backcast. And the trout werewonderfully responsive.
The fish of theMadison were in part hatchery-raised, in part wild, but the river gave themsuch an ideal environment that even the hatchery-planted fish soon acquired thefighting ways and even almost the rich coloring of wild trout. For the riverwas always full of food; it stayed cool enough to keep the trout healthy andactive, and it abounded in natural cover.
The quake changedthe picture drastically for a time. Eighty million tons of a 7,600-footmountain toppled into the Madison. A 3,000-ton boulder and another onlyslightly smaller were hurled across the river and up a mountain on the otherside to come to rest almost a mile away. The massive earth slide dammed theriver and formed a new body of water, Earthquake Lake. The shock that causedthe slide tilted Hebgen Lake, seven miles long, so that cottages on one sidewere inundated and cottages on the other side were left high and dry. The shockwas felt in nine big western states and parts of Canada. Seven weeks after thefirst tremor, which came at 11:38 on the night of August 17, 1959, the regionstill was experiencing a minimum of 55 shocks a day. Now, two years later, theearth continues to tremble but in diminuendo, perceptible only on seismographrecorders. It took 20 years for the Helena quake of 1935 to calm down, and thisone was much bigger. On the Mercalli scale of 12 it had an intensity of 10. OnRichter's magnitude scale it hit 7 1/10, compared to San Francisco's 8¼.
No resemblance totrout streams
After the quake,the rivers in the region ran at flood stage, all of them dangerously silted,some of them dyed a bright yellow with a red tinge. They bore no resemblancewhatever to trout streams. The flooding and silting continued through the fall,until the heavy frosts of winter, when the water on most rivers at last beganto clear. Most likely the floods were caused by compaction—a sudden squeezingof water-holding spaces deep in the trembling earth, very like the squeezing ofa wet sponge. In some places, well away from surface water, a curious blue-graymud bubbled up through the dry earth.
The effect onMadison River fishing of the flooding and silting that followed the quake couldnot be assayed with any reliability until this year. Obviously such anupheaval, with one of its epicenters almost in the bed of the stream itself,must have affected the fish in some fashion, and some changes in the fishingwere indeed observed last year. Now, however, the time has come when a judgmentcan be made. Guide Homer Fisher of Bozeman has fished the Madison and Gallatinfor many years from spring till hunting season. He summed up the happynews:
"The troutthis year have more girth for their length," he said. "They are fatterand stronger than ever. I think the quake stirred up more food."
Stirred up ornot, there is no reason now for any Madison trout to go hungry. At the start ofa six-mile float on a rubber raft Guide Ed Maynard of The Channels, near Ennis,demonstrated this by screening up some bottom. The screen came up covered withwriggling hellgrammites whose imitation, the weighted black Woolly Worm, is afirm favorite of Montana fishermen. The sporting-goods stores in towns likeBozeman, where outfitters are as thick as flies during a hatch, sell thousandsof them.
The Stetsoned,pistol-packing Fisher has one special favorite, the Lady Mite, which he fisheswet. But he holds also to a theory that has a certain plausibility. He believesthat a male fly should be shown following a female, the latter used as adropper.
"The fish seethat all the time," he explained, "and it looks natural."
Harry W. BakerJr., manager of the U.S. Fish and Wildlife Service hatchery at Ennis, agreesthat the river has improved.
"First ofall," Baker explained, "the quake shut off the main source of turbidwater, which came out of Cabin Creek and Beaver Creek, above the new QuakeLake. In normal years the Madison did not clear up until about July I. Notuntil then was it any good for fly-fishing. Now it will be clear between June 1and June 15. In past years a heavy rainstorm would make it muddy for two orthree days, but this is no longer true. The resultant increased lightpenetration has produced more moss, which results in more food for the fish.The fish are growing much faster than previously, particularly the fish we haveplanted.
"The river isat a lower temperature, too. Quake Lake has not exceeded 56° as against aprobable 60° for that section of the river in previous years. The Madison insome parts has gone to 76° and better at times, but we have not yet found itabove 70°, in spite of this summer's drought. [The temperatures apply to thearea near Ennis. The river gets warmer farther downstream.]
"To guess atthe cause of this cooler water, I would say that the water at Quake Lake, whichgoes down to 180 feet at its deepest, may be flowing out more from the bottomthan from the top."
Baker believesthe silting did no permanent damage, though it did destroy many small fish. Bigtrout withstood the abrasive action of the silt on their gills. Fish in the eggstage were buried and so protected against the silt. That, in Baker's opinion,explains why so many fish taken last summer were either very big or very small.Now the balance is about back to normal.
Baker has beenplanting only rainbows and grayling, since the wily, suspicious browns of theMadison are holding their own. They also are running slightly bigger than therainbows.
"If a streamcensus shows 75% browns and 25% rainbows," Baker says, "then a creelcensus will show just the opposite. One probable reason is that fishermenunconsciously select lures that will attract rainbows bright stuff. What getsthe browns are dark flies like the Wulffs, whereas the gray squirrel tails,which are very popular, will take almost nothing but rainbows."
For this reasonBaker has been planting 1,000 rainbows per mile of stream over the 60-milestretch covered by his hatchery. He has also put 25,000 grayling into EnnisLake, from which they move 20 miles upstream to spawn.
Baker's opinionof the Madison is as ecstatic as that of most who have fished it.
"For a streamas accessible as the Madison," he says, "I don't think there isanything like it in the world for season-long fishing."
Any rumors thatthe Madison has declined are clearly false, as false as one strange tale thatcropped up this spring. Suddenly Whit Lake began to produce a preponderance ofalbino rainbows. Hundreds of these pallid fish were caught, and the word wentout that, just as human hair is supposed to turn white from fright, so thesefish had been scared out of their natural coloring by the quake.
It's a shame tospoil the yarn. The albinos were hatchery culls planted in the lake to see howthey would make out. They are doing very well, thank you, and so is themarvelous Madison.
PHOTO
MASSIVE SLIDE of 80 million tons toppled into the river, burying cottages forever and damming the stream to form Earthquake Lake (in background). Since then a channel has been cut through the slide.