Bear Courtship

Bearcam is back! While brown bears fishing at Brooks Falls are the cam’s main attraction, bears also engage in another important event—courtship. Bears make new cubs at this time of year.

Courtship is a conspicuous part of bear life in spring and early summer. Sometimes a male bear encounters a female bear at the right time and they copulate immediately, but more often bear courtship is a prolonged affair. From an ursine perspective, courtship is a process in which a male follows a female in estrus, habituating her to his presence until she is ready to mate.

large bear (right) follows smaller bear through grass

A large adult male, 856 (right), follows 708 Amelia while she was in estrus in 2013.

Courting pairs are easy to recognize by the male’s conspicuous and persistent behavior. A male bear recognizes an estrous female by her scent. He then walks behind her, shadowing her movements like he has a laser sight affixed to her rump (hormonally, the simile may not be far from the truth). However, bear courtship contains neither romance nor effort from the male to attract the female. He’s simply biding his time.

Copulation takes place only when the female is ready, which may not be for days. (The longest courtship I ever noted at Brooks River was 10 days.) It’s certainly not uncommon to see a male following a female for hours and hours.

Over those hours and days, the male follows her, guarding his access for the opportunity to mate. If another male of equal or greater dominance catches the female’s scent, then the two males may engage in a violent fight. Male testosterone levels peak, coincidently, in June as well. In late spring and early summer, fresh wounds on dominant adult males may be battle scars from a fight for access to a female bear. Bigger can be better in the bear world.

large bear with wound on cheek sitting in water

In June 2015, 814 Lurch returned to Brooks Falls missing an ear and with a large wound in his right cheek. These wounds could have been received during a fight with another male over access to a female.]

The victor continues his slow pursuit until the female decides the time is right. Outside of the mating season, male bears pose real threats to smaller females (sometimes, albeit very rarely, killing them) so the close, persistent proximity of a large male must be alarming at first. Eventually, hormones and habituation to the male overcome her initial trepidation.

Even then, the female may not be ready.

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Copulation lasts upwards of twenty minutes. Brown bear females are promiscuous and may mate with more than one male. Her estrus cycle isn’t a single event. She can have several over the mating season, which generally runs May through July. Female black bears may be induced ovulators, so brown bears could be too, and while no evidence of multiple paternities has yet been confirmed at Brooks River, a single litter of cubs could have multiple fathers.

mating bears

218 Ugly mates with 402 at Brooks Falls in 2010.

If mating is successful, the fertilized egg divides only a few times before entering a state of arrested development in the mother’s uterus. Only after she enters the den in the fall will the blastocyst begin to grow again. Through this delayed implantation, female bears can focus the rest of their summer efforts gaining enough fat reserves to survive hibernation. This allows cubs to be born in mid-winter when they are most protected in their mother’s den.

Over the next few weeks on bearcam, watch for male bears to doggedly follow single females. This is the most conspicuous sign of bear courtship, a season is marked by competition, conflict, persistence, and the promise of another generation of bears at Brooks River.

Someone’s eating the berries

In low elevation areas at the foot of the North Cascades, salmonberries are quickly ripening and I have plenty of competition in the race to harvest them.

ripe salmonberrySalmonberries (Rubus spectabilis) are moderately tall shrubs with compound leaves and bright magenta flowers. The flowers later produce large, raspberry-like fruit in various shades of yellow, orange, or scarlet. According to Cascade-Olympic Natural History, the plant’s common name derives from the fruit’s ability to cut the greasiness or fishiness of salmon, not from their color. Like many sugary, wild fruits, they are relished by more than humans. Recently, other critters have beaten me to the choicest berries.

stem of plant missing its fruit

Increasingly often, I find salmonberry shrubs stripped of their ripe berries.

 

Bears, of course, will eat salmonberries, but most of the berries I’ve seen have been plucked a bit too delicately to be the work of a bear. Bright red or yellow berries aren’t just an advertisement for mammals. They attract birds as well. Cedar waxwings, in particular, are pronounced frugivores and I recently watched a few in the act of stripping a salmonberry shrub clean.

I’ll gladly yield the fruit to these birds, since they’re doing the legwork (or is it wing-work?) to disperse the seeds. In the waxwing’s digestive tract, the seeds are carried far and wide, and if the seed is extremely lucky the bird will deposit it in a moist, sunny spot with rich soil.

More than waxwings influence this plant’s reproduction, however. Earlier this spring, I watched many rufous hummingbirds visit its large magenta flowers.

magenta colored flower with five petals

The salmonberry flower.

Salmonberry blooms relatively early in the spring (I found it in full bloom in mid April this year), a time when few other hummingbird flowers are present. Salmonberry plants aren’t exclusively pollinated by hummingbirds, but I watched hummingbirds frequently visit more than one patch of salmonberry blossoms this spring, so it may be an important early source of nectar for them.

In blossom and in fruit, salmonberry is tied to birds. Have you noticed similar connections in your local ecosystem?

Deer Fawn

mother deer and fawn

Within and along the foothills of the western Cascades, black-tail deer have dropped their fawns. Once in a while, I’m lucky enough to see one.

Cute right? I often see deer, but I rarely see fawns. There’s a good reason for that.

Deer fawns are very small and vulnerable. Unable to outrun predators, they utilize a simple and effective defense—lie down and remain still until the coast is clear. In this manner, the newborn deer can be so cryptic and their scent so faint they often avoid detection.

No defense in nature is foolproof, however. Fawns can be an important food source for bears, coyotes, and bobcats. In this evolutionary arms race, camouflage and stealth is counteracted by a keen sense of smell, skill, and sometimes luck.

If you are lucky enough to stumble upon a deer fawn, please leave it be. The fawn may have laid down because you approached, but mothers sometimes hide their fawns in brush, returning periodically to nurse. Most likely, the fawn you just found is not abandoned or orphaned. Mother is nearby and when you leave, the doe will return.

 

Flower, You Stink

Throughout much of temperate North America, late spring and early summer is a wonderful time to enjoy wildflowers. I like looking at plants for many reasons, but recently I’ve begun to think more carefully about their smell. I’ve been sniffing plenty of flowers lately, and not all are pleasant.

Most flowers that we notice need a pollinator, but pollinators aren’t volunteering their services. They seek a reward for the effort to help the plant complete its reproductive cycle. Most of the time, the reward comes in the form of pollen or nectar or both (although there are some amazing examples of plants deceiving their pollinators). Other than visual cues, scent is one noticeable way flowers advertise their wares. Ever smell a wild rose, for example? They are sweetly fragrant, even from a few meters away, and are popular with bees and butterflies, who seek out their pollen and nectar and pollinate the plant in the process.

two rose flowers with pink petals

Rosa nutkana, the Nootka rose.

I’ve sampled the perfumes of many plants recently, giving me a tangible way to understand their different reproductive strategies. The scent of flowers, not surprisingly, ranges from non-existent to downright stinky.

Lupine, another plant popular with butterflies and bumblebees, is very odorous, smelling sweetly florid and very noticeable while walking through a meadow. The same goes for snowbrush ceanothus (Ceanothus velutinus), whose flowers attract a wide variety of insects.

cluster of white ceanothus flowers at the end of a twig

Ceanothus velutinus, commonly called snowbrush ceanothus.

Hawthorns (Crataegus sp.) and black cherry (Prunus serotina) are faintly malodorous, at least to my nose. Consequently, they attract a different suite of pollinators than roses even though they are in the same family (Rosaceae). Bees visit these plants but so do lots of flies.

flowers, Prunus serotina, Moraine State Park_05182017To increase the skink level another notch, take a whiff of mountain-ash (Sorbus sp.) or yarrow (Achillea millifolium). Mountain-ash and yarrow are in different plant families, Roseaceae and Asteraceae respectively, but they share one trait: their flowers smell like shit.

flowers, Sorbus scopulina

The first time I discovered the scent of mountain-ash, I thought I had stepped on a dog turd.

fly on cluster of white flowers

Yarrow is surprisingly stinky, which would explain why flies that you’d find on scat also visit this plant’s flowers.

Why smell like animal scat? Not all insects seek the same odors. Many species of flies, as we know, are attracted to carrion or scat. Flowers that mimic these odors are often seeking pollination from flies. From the plant’s perspective, it doesn’t matter what insect provides the pollination as long as the work of pollination gets done.

There’s sweet, there’s stinky, and then there’s unscented. I couldn’t detect the any scent from wild ginger (Asarum caudatum) flowers, but the plant was very odorous and smelled, well, like ginger. Its flowers hide on the ground, but this plant may be self-pollinated more often than not.

maroon colored flower among fallen leaves

Asarum caudatum, wild ginger, flowers hide on the forest floor.

Orange honeysuckle (Lonicera ciliosa), from my limited observations, is pollinated exclusively by hummingbirds. The bright red-orange flowers are striking and easy to see, but have no scent, at least none that I could discern. Hummingbirds have little to no sense of smell. If your flowers, like the wild ginger’s, are mostly self pollinated or your pollinators can’t smell you, then there’s no need to expend energy producing scent.

When we walk into or even near a floral shop, the air smells strongly of perfume, an odor most of us would describe as florid. In nature though, the perfume of flowers is extremely varied. They smell fruity, sugary, stinky, rotten, inodorous, and everything in between. Flowers, in my opinion, are nature’s most conspicuous display of sex and scent is a technique plants use to get what they need—pollination—to reproduce.

 

Cross Country By Rail Continued

In my last post, I left Bellingham, WA and crossed the Cascade Mountains via Amtrak’s Empire Builder. On day two of the journey to Pittsburgh, the route and landscape would prove to be even more contrasting than the previous twenty-four hours.

Overnight the train route crossed eastern Washington and Idaho. I woke around sunrise to a foggy scene along the Kootenai River. The river along this stretch harbored few rapids that I could see, but it was brimming with muddy water. Spring and early summer is the season of high runoff in the Rockies.

river flowing through foggy valleyThe train soon left the Kootenai River and passed through the Salish Mountains to the Flathead River valley. After Whitefish, Montana we began a slow climb toward the continental divide. Along the middle fork of the Flathead River, between Glacier National Park to the north and the Great Bear Wilderness to the south, lies one of the most scenic stretches of rail on the route. Every bend provided new views of the snow-capped mountains bounding the narrow valley.

view of forested mountainsWhile I enjoyed the mountain scenery, for me the real highlight of this section was the stark contrasts in vegetation and climate. The low valleys on the west side Glacier National Park capture enough precipitation to support the growth of species also found within the wet forests Washington’s Cascades. At West Glacier I caught glimpses of the some of the eastern-most stands of western red-cedar (Thuja plicata). This species, you could say, likes it feet wet and it won’t grow where soil moisture is too low. In this part of North America, a lack of suitable habitat squeezes the red-cedars into narrower and narrower confines, and it quickly disappeared as we traveled east.

Western red-cedars wouldn’t be the only species to vanish in the next fifty miles. On the approach to the continental divide, lodgepole pine (Pinus contorta) and Douglas-fir (Pseudotsuga menziesii) predominated. Lodgepole pine was especially abundant in areas that had experienced forest fires in the last two decades. As the train crossed the continental divide at Marias Pass (el. ~5200 feet) the forest began to disappear, partly from the elevation (treeline was only a thousand or so feet higher) and largely from increasing aridity.

Terrestrial habitats often intergrade slowly, mixing in quilted patches before one finally yields to another. At East Glacier, Montana though, the montane Rocky Mountain forest seemed to simply end where the short grass prairie began. Here is one of the most dramatic terrestrial biome shifts to be found in the United States.

rolling prairie with snow-capped mountains in backgroundLike the Cascades, the Rocky Mountains create a strong rain shadow across northwestern Montana. Browning, MT, east of the mountains, receives only half the precipitation of West Glacier. For the next thousand miles across Montana and North Dakota prairie dominated where the land was not cultivated or otherwise appropriated by people. The only trees were either planted or grew along creek and river bottoms where their roots could tap into a shallow water table.

prairie and wheat fields across north central MontanaWildlife became easier to spot on the open prairie. Through Montana the railroad took us just south of the true prairie pothole region, but many of the low-lying areas adjacent to the track held water. Every little puddle seemed to harbor a few pairs of ducks and geese. I casually spotted at least ten waterfowl species during the day. Undoubtedly more used the habitat. I just failed to see them. Small prairie dog towns, frequented by red-tailed and Swainson’s hawks, occupied some of the ranching areas. I counted at least two-dozen pronghorn grazing or resting small, scattered bands.

In eastern Montana, badlands appeared in the distance and became more prominent as we approached and crossed the North Dakota state line. Parts of this area are rich with fossils and I wanted more than a little bit to poke around the hills for ancient bones.

badland bluffIn North Dakota, fracking wells became a prominent sight as the sun set.

oil wells silhouetted by the setting sunOn the morning of my third and final full day on the train I woke up somewhere in Minnesota where the prairie had long since yielded to cornfields. This was, historically, a battleground between prairie and forest. In this area, where precipitation is great enough to support tree growth, fire was the prairie’s greatest ally. Periodic burning kept the forest at bay. After American settlement, the prairie was plowed and fires suppressed. Along this ecosystem margin today, you’re more likely to see farm fields bordered by trees than a patchwork of prairie and forest.

Spring was also much less advanced in west-central Minnesota compared to the Puget Sound area where my trip began. Quaking aspen was washed with small vibrant leaves but some of the paper birches had barely broken bud.

For over a hundred miles south of Minneapolis and St. Paul, the route followed the Mississippi River where tall bluffs bordered the river valley…

wide river with tall bluffs in background…and the floodplain forest drowned in water.

flooded marsh bordered by forestThe train crossed the Mississippi one final time at La Crosse, WI. Heading upland into central Wisconsin, jack pine (Pinus banksiana) appeared on sandy soil. This species is essentially the eastern equivalent of lodgepole pine and the two hybridize where their ranges overlap. Like it’s western sibling, jack pine is well adapted to fire, often holding serotinous cones on its branches for years before fire melts the cones’ resin and releases its seeds.

forest and rolling hills

You’ll have to take my word for it: Those are jack pines in the middle ground.

East of Madison, the landscape quickly became suburbanized then urbanized as we approached Milwaukee. We never seemed far from Lake Michigan, but I only caught a couple of glimpses of the great lake.

I transferred trains in Chicago for the final leg of the journey to Pittsburgh. Through Gary, Indiana, the land remained very urban with the exception of the forested dunes on the inland side of Indiana Dunes National Lakeshore. Night hid most of Indiana and all of Ohio. After a rough night of sleep, I arrived in Pittsburgh at 5 a.m.

There’s a lot of sitting on a railroad trip from Puget Sound in Washington to Pittsburgh and I felt very antsy, so I capped off my first day in town with a fifty-mile bike ride on the Great Allegheny Passage. The exercise and change of pace was welcome, but so was watching the landscape through the train window.

Cross Country By Rail Day One

Since I live across the continent from most of my family, I’m obliged to return east periodically. During my time in Alaska I flew almost exclusively on this migration, primarily because it was the most expedient way to get to where I needed to go. If I have the time though, I’d rather travel by other means. With some time to spare before my summer job at North Cascades National Park begins, I traveled by train from Bellingham, WA to Pittsburgh, PA.

I’m not a train fanatic, but the railroad allows me see a good deal of the landscape and perhaps some wildlife without the risks involved with highway driving. On the train, I could sit in my seat and gaze eagerly out the window to watch the landscape pass by. My first wildlife sighting began even before I stepped onboard.

While waiting for the train in Bellingham, I watched a crow land in a parking lot with something large in its bill. This was nothing unusual as crows are fond of scavenging garbage, but as soon as the crow landed I noticed its prize was moving. I hurriedly yanked my binoculars out of my daypack to get a better look.

The crow had caught and was killing a semi-neonate cottontail rabbit. After it dispatched and partly consumed its prey, the crow returned to catch and kill another kit. With more than it could eat, the crow cached pieces of the rabbits in nearby trees and shrubs. It was a fairly gruesome death for the rabbits, but crows gotta eat too.

view through fence of crow

Life and death struggles happen even in city parking lots.

Once onboard the train and traveling from Bellingham to Seattle, I witnessed no more battles between predator and prey. The rest of the ride, in fact, was quite pleasant. The Cascade route provided plenty of views of Puget Sound, where many birds lounged and fished in the water near shore. I enjoyed glimpses of birds like blue herons, cormorants, gulls, more crows, and brant.

view of water with clouds and boulder in middle foreground

Puget Sound is a glacially carved trough. The boulder in the middle foreground is likely a glacial erratic.

Where I couldn’t see the water, the route often passed through rich farmland where large rivers like the Skagit and Snohomish have deposited broad floodplains.

Fallow farm fields and farmhouseAfter transferring to the Empire Builder in Seattle, my route reversed north before it turned east up the Snohomish and Skykomish rivers valleys toward the Cascade Mountains, which were quite showy under clear skies.

Farmland with view of tall snowcapped mountains in backgroundThis section of rail, besides letting me enjoy scenes of lush forest, provided a conspicuous example of habitat changes due to climate, particularly the Cascades’ rain shadow effect. When moisture-laden storms from the Pacific reach the Cascades, the rising air cools and drops a considerable amount of its moisture on the west side of the mountains. Far less remains to wet the mountains’ eastern slopes.

Skykomish, WA at 900 feet in elevation, for example, receives a whopping 91 inches of precipitation per year. The forests of this valley, except where recently clear-cut, are lush and thick and moss hangs prominently from stout big leaf maple branches.

Forests on snow-covered mountainside

Lush forest cloak the western slopes of the Cascades.

 

Around 2900 feet in elevation, the train entered an eight-mile long tunnel and passed underneath the Cascade crest. When the train exited the tunnel on the east side of the Cascades, the forest was noticeably different. Trees were sparser and included a higher proportion of drought tolerant species like ponderosa pine.

Sparsely snow covered mountain

Many mountainsides east of the Cascade crest are noticeably drier and less forested than equivalent areas to the west.

As the train descended the Wenatchee River valley to the Columbia River, the climate became drier and drier. Soon enough, sagebrush and bitterbrush mixed with widely scattered trees as we approached Wenatchee around sunset. About 780 feet in elevation, Wenatchee receives only 11 inches of annual precipitation. Along the Columbia River, as night fell, the route crossed a dramatically drier environment compared to the lush forests not far to the west. I could see few trees except those planted by people.

Darkness concealed central and eastern Washington’s landscape, which I knew would happen but was still disappointing because I missed viewing any of the unique and spectacular channeled scablands. I went to bed looking forward to more sightseeing.

In a future post, I’ll describe days two and three on the train where the land continued to offer more reasons to be glued to the window.

Nests and Fledglings

Standing in a driveway in western Pennsylvania yesterday, a robin flew quickly from a garage as I walked by. Today I watched a robin, probably the same as yesterday, flush from the same place. Both times the bird flew maybe ten meters before perching and making several alarm calls. Both times it remained nearby, calling, until I left. The robin had a good reason to stick around. Inside the garage, in an old hanging basket, it had a nest with several mostly naked chicks.*

naked robin chicks in nestAmerican robins, due to their tolerance of humans and our habitations, are fantastic birds to seek out in the spring, especially if you want to watch the nesting process. Last year, a robin built a nest under the roof eave of my house. It was a perfect location for the bird—secluded, hidden, and difficult for predators to access—and for me since the nest was only two feet outside of my bathroom window. It was a great opportunity to witness the growth and behavior the chicks in the nest, and I could watch it with minimal disturbance to the birds. Several times a day I watched the nest, the highlights of which I compiled into a video.

For American robins, the timespan from the start of incubation to fledging is very short, generally less than one month total. All the robins in the video above fledged within 13 days of hatching, growing nearly to the size of their parents during that short time.

Adult robin (upper left) and fledgling robin (lower right) perched on tree branches. Tree is big leaf maple.

A robin fledgling (lower right) follows one of its parents a day after fledging.

 

After these young songbirds fledged, their parents still had work to do. The fledglings followed mom and dad, continuing to beg for food, and the parents had to keep a watchful eye for predators. It’s difficult job and most robin chicks don’t survive to adulthood.

Once they leave the nest, fledglings of many species aren’t silent. I found this yellow-rumped warbler fledgling last spring by its impressively loud begging calls.

In temperate North America, mid spring to early summer is an exciting time to watch birds. The next time you’re outside, watch and listen carefully. You may find many birds very busy with the business of reproduction and survival.

*Please watch bird nests ethically. The nesting season is a stressful and difficult time for young and adult birds alike. Adult birds will likely view you as a threat. Some birds are very sensitive to disturbance and may abandon their nest and young. Careless footsteps may trample eggs or chicks of ground nesting species. Some birds, like killdeer, will expend considerable energy trying to distract and lure you away from their nest. Keep enough distance between you and the nest to avoid disturbance and watch through binoculars.

Trail Cam

In February, I discovered wolverine tracks in the snow. After mentioning the tracks to a resource management specialist at North Cascades National Park, we decided to set up one of the park’s motion sensor trail cams hoping to capture photos of wolverines or any other animals that might wander by. The cam didn’t capture images of any wolverines, but it did reveal the presence of other large critters. (In this post, all photos from the trail cam are courtesy of North Cascades National Park Service Complex).

On March 20, I mounted the cam on a tree with a clear view of an unplowed, snow covered bridge over Stehekin River, surmising that the relative ease of crossing the bridge would funnel wildlife across it.

Trail cam mounted on Douglas-fir tree

After setting up the cam, the first photos capture me skiing away.

GIF of person skiing across bridge

Nothing appears on the cam until March 30 when a mountain lion waltzes by!

Mountain lion walking on snow. 2017-03-20, 9:52:47 AM, 33˚F

GIF of mountain lion walking across snow

I was surprised the mountain lion was in this habitat during late March. Many deer, the primary prey for Washington state’s cougars, inhabit the lower Stehekin River valley, but I had seen no tracks of those animals anywhere within five miles of the bridge. The four feet of snow in this location was still prohibitively deep for deer. Perhaps this was a male seeking females or simply one of the resident lions moving through its territory. I’m not sure, although I found a pair of lion tracks a couple of miles north along the Pacific Crest Trail three days afterward.

After swapping out the cam’s memory card on March 23…

hand and part of person's face in front of camera, snow in background

…I left the cam alone until April 3. When I returned I noticed some large, semi-fresh tracks post-holed across the bridge. Backtracking the animal’s movement, I found it walked right under the cam before crossing the bridge. Interestingly, the cam took many photos of an empty bridge the evening before I arrived. Something had nudged the cam, triggering it for 13 seconds according to the photos’ time stamps. One photo in the sequence is completely black as if something briefly covered the lens.

GIF of trail cam sequence. Cam is nudged by animal out of frame.

The culprit was revealed a few seconds later.

black bear walking on snow with nose to the ground. 2017-04-02, 7:24:44 PM, 36˚F

 

GIF of black bear walking across snow

Bears are extremely curious. This one found the cam and investigated it seconds before walking across the bridge. Since black bears in the northeastern corner of the North Cascades begin to emerge from hibernation in early April, it may have been fresh out of the den. On the other side of the bridge it’s tracks continued straight up the hillside disappearing into the forest.

I know these animals live here with me. I see their tracks and scat somewhat often, but I encounter the living individuals less frequently. For me, the cam provided an enjoyable, albeit brief, glimpse into their lives.

Lake Chelan

If you’ve never been to Stehekin, it takes some time to get to. Lying at the head of Lake Chelan, Stehekin is only accessible on foot, by boat, or plane. I’ve traveled in and out many times over Lake Chelan in the past year and each time, it gave me time to witness the climatic, topographic, and glacial changes that make this area biologically diverse.

View from ridge looking into deep valley with lake

Upper Lake Chelan and the lower Stehekin River valley seen from a ridge above Rainbow Creek.

Lake Chelan is cleaved into the heart of the North Cascades and is one of the more spectacular places in the area, biologically and geologically. Most people who arrive in Stehekin in Lake Chelan National Recreation Area do so via ferry. When the ferry motors away from Fields Point Landing, about one third the distance from Chelan to Stehekin, it leaves a relatively dry habitat with sparse tree cover, but this can look lush compared to areas farther down lake. At the lake’s outlet, the town of Chelan receives only 11.4 inches (29 cm) of precipitation per year. It is a downright arid place.

Mountain slopes with few trees above lake

Sparse vegetation along the lower half of the lake is the result of an arid climate with hot, dry summers.

As the boat continues up lake, stands of ponderosa pine and Douglas-fir slowly thicken. At the elevation of the lake (1,100 feet, 335 meters) however, several factors continue to limit tree growth even along the lake’s upper reaches. Fires frequently burn the slopes while bare rock and sheer walls inhibit soil formation. Summer drought is common with scant rain and hot, dry temperatures that bake the lake’s western and south facing slopes. During spring, the mountainsides are flush with water from snow melt, but in late July and August the soil will become so desiccated it rises like powder under your footsteps.

Snow covered mountain with dead standing trees

In 2015, wildfires burned large areas near Lucerne, a small village on the lake.

Mountainside with dead standing trees and snow filled gullies

With ample snow melt, water is easy to find on the mountainsides next to the lake. In mid to late summer however, many of the gullies will become completely dry.

The North Cascades are famous for prodigious snowfall and plenty still clings to the mountains at this time of year. During the last glacial maximum, nearly the whole lake basin was filled with a glacier that carved it into a land-locked, steep-walled fjord.

In its middle reaches, Lake Chelan plunges to great depths. The mountain topography on either side of the valley restricted the glaciers outward flow, but not its forward movement. The tight topographic pinch created by the mountains enhanced downward erosion by the glacier. The lake basin, averaging only a mile wide over 50 miles, was greatly over-deepened, even reaching below sea level. At its deepest point the lake is almost 1500 feet (456 meters) deep. (More info about Lake Chelan’s underwater topography.)

Diagram of lake basin. Y axis is depth in feet and and X axis is length in miles

The upper basin of Lake Chelan is its deepest and most voluminous. Near mile 16 on the horizontal axis lies a submerged glacial moraine.

Section of bathymetric map of Lake Chelan. Contour Lines in 100 foot intervals. Greatest depth 1486 feet.

The steep mountain topography continues underneath the lake.

Steep mountain above lake

Sheer cliffs plunge steeply into Lake Chelan above the deepest areas of the lake. Below the boat on which I stand, the water is over 1,000 feet deep.

The volume of the former glaciers is apparent by looking at the shape of the mountains. Where glaciers overran the mountains, the ridges and peaks are smoothed over and somewhat rounded. Mountains that were tall enough to escape complete glaciation remain craggy and jagged. Measured perpendicularly from the deepest area on the lake to the crest of nearby mountains, vertical relief can reach 9,000 feet (2,744 m) and glaciers filled most of the space in between.

Snow covered mountain peak and ridgeline

Knife-edged ridges and peaks were not completely glaciated. Glacier ice eroded lower ridges, smoothing them over.

Looking at a map of Washington before I arrived here, I didn’t fully understand or appreciate the area’s diversity or its glacial story. Here, arid adapted species like sagebrush can live on hot, dry rocky outcrops just a short distance away from a cool, moist ravine with western red cedar and thimbleberry. Glaciers left their mark up and down the lake, accentuating topography even further. Lake Chelan is Washington’s inland fjord surrounded by, perhaps, the most diverse habitats in the whole North Cascades ecosystem.