Fish and Fishing Waters in Glacier National Park

FISH AND FISHING WATERS IN GLACIER NATIONAL PARK

By A. S. Hazzard, Ph.D., Mich. Inst. for Fisheries Research

(Written especially for the "Drivers' Manual". Dr. Hazzard spent two summers in Glacier for the U. S. Bureau of Fisheries)

During the summers of 1932 and 1934 a survey was made of the lakes and streams of Glacier Park to determine conditions for fish life and to outline plans for fisheries management in this unique area.

Field parties made up of fisheries biologists visited all of the streams and lakes accessible by road or horse trail and in addition a few of the primitive waters which could only be reached on foot. The survey was conducted by the U. S. Bureau of Fisheries with assistance from the National Park Service.

No formal report of the work has been published, but the Bureau has authorized preparation of the following popular account of the data secured.

The Streams

The streams of Glacier Park are, as a whole, disappointing to the angler. This is due to a number of causes. Except for the branches of the Flathead River, the streams are mainly small and extremely rapid. The many beautiful waterfalls and cascades seen everywhere in the Park are evidence of this. While adding to the attractiveness of the Park, they do not provide very good homes for trout. The falls prevent free movement of the fish up and downstream and the swift water furnishes very few resting places for fish.

Many of the streams dry up entirely during the winter months, when the glaciers and snowbanks which feed them cease to melt. This probably explains why such waters as the Two Medicine River above the middle lake and upper McDonald Creek, though ideal in appearance during the summer, do not carry a good stock of trout. But there are other reasons. Some glacier fed streams carry quantities of rock flour which makes them perpetually roily, preventing the proper development of fish food. Furthermore, and this is extremely important, most of the streams in the Park have been found to be too cold to produce good crops of trout. Although this may sound paradoxical, it has been determined that trout do not grow well unless the water temperature ranges from 55° to 65° F. during the summer months. Many streams were found which never reached 55° even during the warmest days in summer. A good example is Cut Bank Creek above the Chalet. Only in the beaver ponds and immediately below them does the stream yield any trout worth fishing for.

Another factor which probably makes for poor trout production in streams is the character of the soil through which they flow. Fed by the pure water from snowfields and glacial lakes, they contain very little mineral and organic matter essential to the growth of fish food organisms. Only in the lower reaches do these streams have the proper richness to support the algae which supply the food upon which aquatic insects depend and which in turn make up the staple diet of trout.

Our survey concluded that these are the reasons why the streams of Glacier Park, though adding much to the beauty of the area, provide little in the way of fishing. Planting trout in the majority of these waters would obviously do no good nor is there any other practicable way in which the streams can be improved. The lower ends of the larger streams are worthy of some attention, as are the branches of the Flathead River. In these the cutthroat, including the blueback, the Dolly Varden and on the eastern slope, the eastern brook trout will continue to furnish some fishing to the angler who does not care for lakes.

The Lakes

It is in the numerous and beautiful lakes in the Park that the best conditions for trout and other game fish are found. Nowhere have we seen a greater variety of lakes than in Glacier. The range extends from small, permanently ice-filled lakes in the glacial cirques high in the mountains to over-rich, weed-filled lakes in the lowland. In between these extremes, neither of which is suitable for fish, is a great range of conditions. In Iceberg Lake, although open water is present on part of the lake during August, the temperature at the surface was only 42° and no sign of plant or animal life could be found. Ptarmigan Lake is at an even greater elevation (6,550 feet), but the glacial cirque in which it lies has a southern exposure and consequently the water warms more rapidly. A few cutthroat trout can find a living in such a lake and reach a fair size.

In general, however, the lower lakes are the best fishing lakes and this is due to the factors mentioned in the discussion of streams. They are generally shallower and warmer and have larger drainage basins than the higher lakes. The soil at lower elevations is richer and the waters consequently produce more food.

The lakes of the Park produce the fishing because here the water is spread out and warms rapidly in the shallows and at the surface during the summer even in the higher lakes. Food is produced in astonishing quantity during the brief period of open water and even under the ice our nets took quantities of blood-red water fleas of remarkable size. In the bottom mud, even at depths of 50 or 60 feet, the clamshell Ekman dredge brought up fair samples of midge larvae or blood-worms. Trout feed on these as they swim up to transform into small, mosquito-like flies or upon the adult flies when they light on the water to deposit their eggs. Along the shores, under rocks and logs in many lakes were fresh-water shrimp often in goodly numbers, and wherever these were found the cutthroat and eastern brook (though not the rainbow) trout were invariably fat and vigorous. The wide expanse of lake surface also acts as a collector of terrestrial insect food--the beetles, ants and various flies which have no part of their life cycle in water but which drop there by accident. Stomach examination of trout from lakes demonstrates the importance of this terrestrial food. Forty-three per cent of the cutthroat, 61 per cent of the eastern brook trout, 33 per cent of the rainbow, 10 per cent of the Dolly Varden and 70 per cent of the grayling contained land insects. These insects which fall on the water by accident made up from 4 to 45 per cent of the total food in the stomachs.

In general the shallower lakes in the Park were found to be the most productive. The deep, clear type of lake having a very limited amount of shallow water, such as McDonald Lake, is beautiful to the eye but does not provide the fishing that is found in the shallower lakes such as Red Eagle or Swiftcurrent. We believe this is due in part to the lower food production of deep water as well as to other factors associated with large, clear-water lakes having little shoal, relatively unproductive bottom and which are subject to strong wind action.

The clarity of Glacier Park lakes is remarkable in the extreme. The Secchi disk, a white enamelled plate about six inches in diameter, used by the survey to determine water transparency, could be seen in many waters at depths of from 40 to 50 feet. In McDonald Lake, late in the summer, the disk was still faintly visible at the astonishing depth of 72 feet. Such clear water is beautiful in appearance but its clearness indicates a scarcity of organic matter and fish food.

Fish and Fishing

The fish fauna of Glacier Park is extremely limited. Only 23 species of fish were found by the survey or have been reported, and of these at least three--the rainbow, eastern brook trout, and Lake Superior whitefish--were undoubtedly introduced. The game fish are the native blackspotted or cutthroat trout (two subspecies), the introduced rainbow and eastern brook trout, the Dolly Varden or bull trout, the mackinaw or lake trout, the Montana grayling (which may have been native to certain park waters), the Rocky Mountain whitefish and the northern pike. The land-locked form of the sockeye salmon called the little redfish or silver trout has been planted in Swiftcurrent Lake and adults ready to spawn were found there in 1932. Whether this species has been permanently established in this lake is not known. No trace of the California golden trout planted in a few of the high lakes could be found by the survey. Three or four species of suckers, five species of minnows (including the squawfish, which reaches a weight of four or five pounds), two species of sculpins, a small whitefish (which never exceeds 6 inches in length) and the ling (the only representative of the cod family found in fresh waters) complete the list of fishes in the Park.

This number of species seems small when it is remembered that three major drainage systems head in Glacier Park, but the cold water and presence of many high falls have undoubtedly restricted the natural distribution of fish in this area. In fact, the majority of the lakes on the east side of the park and a number on the west were originally barren of all fish life because falls in the course of the principal streams prevented access to the waters above. Many of the lakes have been planted with trout and now furnish good fishing.

Cutthroat Fishing

Some of the finest fishing in the park is for the native black-spotted or cutthroat trout. This is the dominant game fish of the area and is particularly well adapted to the low temperatures common to most of the waters. Cutthroats up to six pounds in weight have been taken in Red Eagle and Hidden lakes. While the larger fish are generally caught by trolling with fly and spinner or on spoons, they rise to a dry fly when insects are on the water. Unusually beautiful specimens of this native fish were caught in the dark waters of Howe Lake. Since this species, like the rainbow and grayling, spawns in the early summer in the higher waters, few are caught during June and early July. Cutthroats are at their best in late summer and early fall.

Eastern Brook Fishing

Brooks have been introduced into a number of lakes on the eastern side of the park and in Lake Ellen Wilson on the west side. In the majority of waters they do well and are able to maintain themselves by natural reproduction. Middle and Lower Two Medicine lakes furnish very dependable brook trout fishing, as does Swiftcurrent Lake also. Wet flies or spinners are required until the insects appear, but after that it is a poor fisherman indeed who cannot take a nice catch of brooks on flies if he is persistent and knows the waters. In one lake high in the Bighorn Basin, these brook trout are small but very abundant. Conditions for spawning in this little lake are ideal.

The rainbow has been introduced to the park waters and are doing well in the lower lakes. In the higher lakes, such as Gunsight and Upper Two Medicine, these trout become thin after spawning and apparently never recover condition even though food may be fairly abundant. For this reason planting with this species should be confined to the lower, warmer lakes.

Lake Trout Fishing

Glenn and Crossley lakes provide the best lake or mackinaw trolling in the park, though some good catches are taken at times in St. Mary Lake. While surveying the Two Medicine drainage our party received a report that mackinaw had been planted in Lower Two Medicine Lake a number of years previously. To check up on this report a small, experimental gill net (used to sample fish populations) was set overnight. When we lifted this net the following morning, hauling it over the side of our shaky rubber boat, we were astonished to see a 16-pound mackinaw in the meshes. Three others of large size were taken but no small ones, indicating that this species does not spawn successfully although some of the planting had survived and grown fat on the numerous whitefish and suckers in the lake.

Grayling Fishing

The South Fork of the Belly River and Elizabeth Lake yield some grayling to those who are able to make the difficult trip. Morans bath tub (now called Swiftcurrent Ridge Lake) was planted with eyed eggs of grayling years ago. The planting was a success and the grayling did well but have not reproduced because of the lack of any inlet or outlet stream. In recent years suckers and minnows had apparently been introduced accidentally by fishermen who probably brought them in as bait (in violation of the Park rules). In 1934 grayling were extremely scarce and were hardly more than skin and bones--apparently unable to endure the competition. This is a clear though deplorable example of the need for preventing the use of live bait in park waters.

Other Fishing

To the easterner, the catching of a Dolly Varden or bull trout will probably be an interesting experience. Cracker Lake is almost certain to yield some small specimens on flies, while fish up to eight or ten pounds can occasionally be taken by trolling in McDonald Lake or by the use of spinners and worms or minnows in the Flathead River. These fish begin to work up the smaller streams to spawn during late August and early September. Their fight is stubborn but not spectacular and the flesh is inferior to other trout.

The northern pike is abundant in Sherburne Lake and can be taken by casting or trolling with a plug or spoon. This type of fishing is very popular among certain visitors and furnishes a change from trout fishing.

Fish Cultural Operations

The U. S. Bureau of Fisheries in cooperation with the National Park Service plants on the average about a million fish each year. The majority of these are trout, although grayling are stocked in certain waters.

Many of the waters in Glacier Park are well provided with spawning grounds for trout and other species and unless fished more intensively than at the time our survey was made, Nature will maintain as large a stock of fish as the food supply will support. In others, however, notably the high lakes having no tributary streams, a systematic planting of eyed eggs or fingerlings will be necessary to maintain fishing. Being essentially a wilderness park, every effort should be made to maintain the natural wild condition of the fish and the fishing.