Science

High Lakes and High Lake Fishing

By Rex Johnson

Introduction and Origins
Fish Stocking in the High Lakes
Trout Characteristics
Effects on the Ecosystem
Hi-Laker Club

Introduction and Origins

What are the origins of trout in Washington State?

About a million years ago, the ancestors of all modern trout traveled up rivers from the ocean and into streams, tributaries, and alpine creeks. Early records show that many Washington rivers and streams and some lakes had trout in them when the white man first arrived. (2)

How were the mountain lakes in Washington created?

Most mountain lakes in Washington’s Cascades and Olympics were created following the last period of glaciation roughly 10,000 years ago. When the thick ice receded and melted, it left newly created basins, some deep, others quite shallow, which became today’s mountain lakes. Most of these were barren of fish unless there was unobstructed access into the lake via a river or stream. Unfortunately most mountain lakes have waterfalls and other significant barriers to upstream migration. So only a few high lakes ended up with natural trout populations. (3)

What is the definition of a “high lake” or a “mountain lake”?

Washington Department of Fish and Wildlife (WDFW) managers have defined a “high lake” as one situated above 2500-feet mean sea level in western Washington, and above 3500-feet in eastern Washington. These elevations are not arbitrary, but take into account the location of the sub-alpine and alpine zones, as well as other attributes. High lake fisheries are generally managed differently from lowland lake fisheries, with an emphasis on low fish density, and “quality” fishing opportunities. Compared with most lowland lakes, angler use levels are quite low. (3)

How many high or mountain lakes are there in Washington?

According to the commonly accepted definition of a mountain lake, there are approximately 4,700 high lakes in Washington. (3)

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Deep blue lake surround by steep hills covered with fresh snow.
Photo by Rich O’Connell.

Fish Stocking in the High Lakes

How many high lakes have fish?

Of the 4,700 high lakes in Washington, only 1,777 (38%) presently have fish in them. The remaining lakes are fishless for a multitude of reasons. Some of them will not support fish because they are too shallow, or suffer winter or summer kills due to lack of oxygen, or because of other environmental factors. Some are left fishless because good management of the resource and the environment dictates this.

Washington High Lakes
(rounded numbers)
4,700 high lakes
1,800 with fish
1,000 self-sustaining fish populations
800 periodically stocked (17%)

How many high mountain lakes are stocked and how many have reproducing populations?

Of the 1,777 high lakes in Washington that have fish, about 800 are periodically stocked. The remaining lakes, just under 1,000, have self-sustaining fish populations. (3) The present trend of the WDFW is to avoid self-sustaining fish populations in high lakes. There have been too many examples where reproducing fish populations over reproduce, resulting in large numbers of stunted fish and an environmental imbalance. Therefore each lake is carefully surveyed before stocking to be sure that the fish selected will either not reproduce or be self-limiting. Washington is one of the few if only states to manage its high lakes on a lake-by-lake basis.

Who stocks the mountain lakes?

Most of the mountain lakes in Washington were barren since the last ice age, so planting and stocking accounts for the bulk of the fish presence. In the early years trappers, miners, loggers, and outdoorsmen carried trout fry from local streams and stocked lakes for food and sport. By 1914, the United States Forest Service (USFS) was stocking many mountain lakes using mule trains. The Washington Department of Game (WDG) was created in 1933 and continued these stocking programs. The WDG is now called the Washington Department of Fish and Wildlife (WDFW). The WDFW stocks some mountain lakes directly by aircraft, and a few by truck, but by far the majority are stocked by volunteer groups, under the guidance of the WDFW.

Some groups, such as the Back Country Horsemen, use pack animals but most mountain lakes today are stocked by individuals carrying the fry by backpack. The Trail Blazers are the best known group in Washington for carrying juvenile trout into mountain lakes. This club of about 80 members stocks about 100 lakes each year, and about 400 lakes altogether. In other words, they stock about half of all the high lakes that are stocked. Most trout that you find in a mountain lake in Washington were stocked there by someone, usually a Trail Blazer. (3)

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Colorful cutthroat trout in clear water.
Photo by Jed Sires.

Why aren’t all the mountain lakes stocked with fish?

It is important that there be a balance in the natural biota, both for people and for the preservation of nature. Fish may provide you with a positive experience when you go into the mountains, but not everyone feels the same way. Some people want to go to lakes to see other forms of life or to see the mountain lakes as they were before man introduced fish. In order to maintain this natural diversity and balance in the mountains, at present about 62%, or nearly two-thirds, of all mountain lakes are being managed as fishless. (3)

Trout Characteristics

What kinds of trout are in the mountain lakes?

The most common trout to be found in the mountain lakes of Washington are Cutthroat trout, Rainbow trout, and Eastern Brook. Two varieties of Cutthroat trout commonly found are the Twin Lakes Cuts (aka Westslope Cuts) and the Tokul Creek Cuts (aka Coastal Cuts). Most Rainbow trout are of the Mount Whitney variety. There are a few populations of Golden trout, Lake trout, Brown trout, Dolly Varden, Kokanee, Atlantic Salmon, Ross Lake Rainbows, and Arctic Grayling. (3) Of these, only the Westslope and Coastal Cutthroat, Dolly Varden (or Bull trout), and the Ross Lake Rainbows are native to Washington.

What do trout eat?

When it comes to food, trout are typically generalist and opportunists; they will feed upon a variety of prey depending upon what is available. They rely heavily on aquatic invertebrates, primarily larvae of aquatic insects. This includes stoneflies, mayflies, caddis flies, true flies, and at times damselflies and dragonflies. Terrestrial invertebrates such as grasshoppers, beetles, and ants are also prey items. It is typical for one or two sources of food to dominate the diet at specific times on an annual cycle. Although generalists and opportunistic, trout often feed in a very selective manner at any given time. Any serious angler will attest to this!

In some habitats, in addition to the aquatic insect larvae, crustaceans such as freshwater shimp, crayfishes, and tiny free-swimming “water fleas” are important food sources. As some trout become larger, they prey on smaller forage fish. These fish-eating trout are usually able to attain much larger sizes. Since the size of the prey is dictated by the gape of the open month, growing past a certain size opens the door to larger prey items and consequently to further growth.

The amount of food a fish must consume to maintain its body size is dependent upon the temperature of the water. Metabolic rates increase with higher water temperature, so more food must be consumed. Under normal circumstances, a trout must consume about one percent of its body weight per day to maintain its weight; surplus amounts are directed towards growth. The maintenance amount is greatly reduced during colder months and trout are able to subsist on very little, due to the slowing of metabolic functions associated with a decrease in water temperature.(2)

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How fast do trout grow?

Fish grow according to several factors, the most important of which is the availability of food. The following data is taken from a mountain lake with average productivity. (3)

Year 1 2 3 4 5 6 7 8
Size 2-3″ 7″ 9″ 11″ 12″ 13″ 14″ 15″

In lakes with better than average sources of food, it is not unusual to find a 10″ trout after only 1 year!

How long do trout live?

In most environments, the average life span of a trout is six to seven years, but this can be extended up to 25 years or more in some cold, high elevation mountain lakes. Some populations of Arctic Char can live for more than 30 years, and Lake trout often live 60 years or longer. (2)

When do trout reproduce?

In general, Rainbow and Cutthroat trout spawn from late winter to early summer. Brook and Brown trout spawn from late summer to early winter. (2)

Why do some trout have white meat while others have pink or red flesh?

The adage that you are what you eat is very true for trout. Trout with red or pink flesh have most likely been eating copepods or shrimp. Insect larvae usually result in trout with pale yellow flesh. In lakes where the trout eat black leeches, even the skin of the trout can become quite dark. (3)

Effects on the Ecosystem

How do fish affect the ecosystem?

The North Cascades National Park commissioned a scientific study to determine the effects of fish on the natural biota of mountain lakes, such as insects and amphibians. This study was done by William Liss, Gary Larson, and Robert Hoffman. Their results show that high densities of fish, which are basically lakes that have reproducing fish, have a negative effect on the balance of the natural biota in a lake. In contrast, they could find no measurable differences in the biota between lakes that have low densities of fish and those that have never had any fish. In other words, modest numbers of non-reproducing fish have little or no effect on the biota. For this reason, the Hi-Lakers support the present policy of the WDFW to stock low densities of fish in all mountain lakes. (1)

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Blue kayak in middle of a lake surrounded by a sea of green
Photo by Rex Johnson.

Hi-Laker Club

What does the Hi-Laker Club do to help the fisheries in Washington State?

Hi-Laker club members promote no trace hiking and camping techniques, clean up debris left by other people, and provide detailed lake surveys to the WDFW to help it manage the mountain lakes for a quality fishery.

Have a question?

Send an email to Rex Johnson or discuss it in our forum.

References:

(1)Ecological Impact of Introduced Trout on Native Aquatic Communities in Mountain Lakes, North Cascades National Park Service Complex: Phase III Final Report (July 2002)
by William Liss, Gary Larson, & Robert Hoffman

(2) Trout and Salmon of North America, Robert J. Behnke, 2002, The Free Press

(3) Washington Department of Fish and Wildlife’s High Lakes Fishery Management Program, Bob Pfeifer, Mike Swayne, & Brian Curtis, 2001

2 Comments

  1. Reuben

    Last September I fished Venus Lake near lakes trail in the Saint Helen’s blast zone. We caught 4 fish in the 14”+ size and very fat. There was 4 fish heads in the lake that indicated that some other fishermen had been successful as well. The fish I caught were released. There didn’t seem to be a lot of fish but they were all good heathy rainbows

  2. bcurtis

    Reuben, the fish in the blast zone are really interesting. They survived the blast because the lakes were frozen at the time. The lakes received a big jolt of productivity and fish grew to larger sizes than prior to the eruption. Though, they gave those size gains back as productivity decreased.

    It is too bad that some people just leave their fish remains right by the edge of the lake. Please be sure the air bladders are punctured and throw the remains out of sight in deeper water when you clean fish.

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