Avalanche Lake

While at Glacier NP, we camped at Avalanche, where a popular but scenic trail leads from the campsite deeper into one of the mountain valleys in the park. I had hoped to gain a view of the Sperry Glacier from the vicinity of the lake, but the steep topography didn’t allow such a view from the lake basin.

Two views of Avalanche Lake: looking east towards several waterfalls (at
left) and looking west (at right).

Leaving the Avalanche campsite, the trail ascended at a mild slope along Avalanche Creek through a dense conifer forest and after a few kilometers it intersected the oblong lake at the west shore. Here the water was shallow and clear, exposing a dense underwater graveyard of logs covered with the brown ooze of the lake bed. The lake is set in a basin with steep rocky slopes to the north, east, and south. Towards the west end of the lake, the rocky slopes had remnant snow fields feeding several waterfalls and water cascades.

A graveyard of logs in the shallow western
side of Avalanche Lake.

The trail continued along the south shore of the lake with views revealing a splendid turquoise color. The formal trail ended at the southwest corner but by using makeshift log bridges and doing some shallow waling through the icy streams feeding the lake, I continued a bit beyond the trail to the eastern shore.

There were wildflowers at the lake shore - Penstemon, Clematis, asters, and Campanula – and some tiny wetlands at the edge of the forest. The beds of the icy streams were comprised of large cobbles. New snow melt tumbled from the streams sending plumes of turbulence into the otherwise tranquil waters.

References

Phillips HW. 2012. Northern Rocky Mountain Wildflowers. 2^nd ed. Falcon Guides, Guilford CT.

Several flowering species at the east end of Avalanche Lake. From left: Prunella vulgaris (Lamiaceae), possibly Mimulus sp., Campanula rotundifolia (Campanulaceae). 

Two blooming asters (Asteraceae) at Avalanche Lake. Left: unknown. Right: Anaphalis
margaritacea (pearly everlasting).

Rapids along Avalanche Creek.

Interesting rock in cobble bed at shore of Avalanche Lake.

Glacier wildflowers

Flowers were abundant throughout Glacier, from the lower elevations at Apgar and St. Mary’s to above 6500 ft at Logan Pass.

Bear grass (a misleading common name since the species is in the lily family) was probably the most spectacular species, with dense concentrations of flowering plants covering high elevation hillslopes, especially near the Weeping Wall. This is a relatively new species to me. I first encountered it at Mt. Rainier last year. The inflorescence is an elegant spire of white flowers sitting atop a hemispherical bunch of grass-like leaves. The flowers are lightly aromatic.

Bear grass, Xerophyllum tenax. Left: aspiring inflorescences. Right: close up of flowers.

Dotted saxifrage, Saxifraga bronchialis.

Along the Highline Trail that led north from Logan Pass, there were flowers of all colors. Species along the trail included Saxifraga bronchialis, Trollis albiflorus, Myosotis sylvatica, Ribes lacustre, Zigadenus elegans and Calochortus apiculatus. In common with western Washington and Oregon, there was also blooming twinberry (Lonicera involucrata), and thimbleberry (Rubus parviflorus), the latter species with its large palmate leaves and showy white flowers.

Aquilegia flavescens, a yellow-flowered columbine, was an exciting find at Glacier. I’ve long been familiar with the red-flowered sister species, A. formosa, which can be found frequently in a variety of habitats in the Pacific states. A. flavescens has a very similar flower shape to its sister species, nodding flowers and with spurs that protrude at the back of the flower. It is also found in some locations in British Columbia, Washington and Canada.  

Columbines. Left: Aquilegia flavescens at Glacier NP, July 2017. Upper right: A. formosa at
Mary's Peak in central OR, July 2010. Lower right: A. formosa from Big Sur, CA, July 2015.

References

Phillips HW. 2012. Northern Rocky Mountain Wildflowers 2^nd ed. Falcon Guides, Guilford, CT.

Turner M, Gustafson P. 2006. Wildflowers of the Pacific Northwest. Timber Press, Inc., Portland, OR.

Other wildflower species at Glacier NP. From left: Rubus parviflorus, Calochortus apiculatus, and possibly Anemone sp.

Zigadenus elegans, commonly known as "showy death camas", a common
name apparently obtained because the plant is poisonous.

Possibly Myosotis sylvatica.

End of an (ice) age

Jackson Glacier at Glacier National Park.

Several National Parks, including Redwood, the Grand Canyon, and Glacier are named after their most iconic feature. They were established with an eye to the future to protect unique or superlative biological and geological features. In protecting a park’s namesake, whether that is old-growth redwoods or a pristine snowy peak, a whole ecosystem and its diverse components can also be protected from exploitation or excessive degradation. But at Glacier, the glaciers are disappearing.

A glacier is essentially a perennial slow-moving river of ice, formed from the long-term compaction of snow, flowing slowly down a mountainside. The weight of the glacier gradually propels it downslope, while its mass is renewed by new annual snowfall. Technically “official” glaciers have a minimum size of 25 acres. Glaciers are fantastic geologic agents: they carved out Puget Sound in Washington and the stunning Yosemite Valley in the Sierra Nevada for example.  

About a century and a half ago, there were estimated to be nearly 150 glaciers present in Glacier National Park. But by 2015, that number had declined to only 26. The trends at Glacier in northwest Montana track patterns elsewhere: glaciers are shrinking and snowpack is declining. Data from several benchmark glaciers in the northwestern US show mass loss of glacial ice over the last four decades. In the uneven distribution of climate change impacts across the globe, high latitude (particularly Arctic) and alpine regions appear to be warming to a greater degree than other regions.

Left: Map of some of the named glaciers in Glacier National Park and the adjacent Flathead National Forest. Right: Change in the area occupied by Chaney Glacier between 1966 and 2015. Map and figure from USGS.

Change in the Clements Glacier at Glacier NP.
Images from USGS Repeat Photography Gallery.

Glacial growth and retreat is a natural geologic cycle. Currently, the Earth is in an interglacial period, at the warm peak of an alternating cycle of cooling and warming that has alternated periodically over the last 2.6 million years. About 10,000 years ago the last major glacial period ended and the glaciers that covered much of the land in the northern hemisphere melted and retreated, sending sea-levels hundreds of feet higher.

So is the loss of glaciers today part of a normal cycle? Probably not, because today’s rate of atmospheric CO₂ increase (due to human production of greenhouse gases) is unprecedented in recent geologic history. A global increase of 1 to 2°C that may have occurred over centuries or millennia in the past is now on our doorstep in a matter of decades. And because large-scale biological and geological processes can temporally lag the events that drive them, we have probably locked in additional warming for years even were we to cease all additional greenhouse gas emissions tomorrow.

The glaciers and snowfields of Glacier National Park provide the source waters for rivers that flow to the Pacific Ocean, the Gulf of Mexico, and Hudson Bay. The park straddles the continental divide, the cross-roads of the watersheds that collectively cover most of North America. Glacial melt is a particularly important source of water to mountain ecosystems in the late summer when the non-glacial snowfields have already melted.

Long-term change in snowpack throughout the western United States. Red circles indicate areas
 with snow decline. Image from EPA.

Change in the size of the Grinnell Glacier at Glacier NP.
Images from USGS Repeat Photography Gallery.

Driving through the park this month, I saw the lingering snowfields of the higher peaks, with perhaps a glacier or two tucked into the mountains. The melting water fed rapidly flowing streams, waterfalls, and lakes. The only glacier I definitively saw was Jackson Glacier from a viewpoint along the “Going-to-the-Sun” road. Views of other glaciers required more committed backcountry hikes that I didn’t have the time for on the trip.

By emitting so many greenhouse gases into the atmosphere in such a short time, we may be ushering in an era of unprecedented warming across the planet that may affect everything from species distributions to ocean acidification and sea-level rise. The threats to glaciers are a global phenomenon, requiring global action to address. More locally, at Glacier NP and other alpine ecosystems, it remains to be seen how the loss of glaciers will affect ecosystem processes over the coming centuries.   

References

Glacier National Park website

National Snow and Ice Data Center. 2017. All About Glaciers.

US Geological Survey. Retreat of Glaciers in Glacier National Park. 

US Geological Survey. Repeat Photography Gallery.

Snowfield and Bird Woman Falls as seen from the
"Going-to-the-Sun" road at Glacier National Park.