McGregor Mountain (Cascades)
Climate
McGregor Mountain has an alpine climate which supports the Sandalee Glacier on its northern slopes. Weather fronts originating in the Pacific Ocean travel northeast toward the Cascade Mountains. As fronts approach the North Cascades, they are forced upward by the peaks of the Cascade Range, causing them to drop their moisture in the form of rain or snowfall onto the Cascades (Orographic lift). As a result, the North Cascades experiences high precipitation, especially during the winter months in the form of snowfall. During winter months, weather is usually cloudy, but, due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer.
Geology
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/McGregor_Mountain.jpg/290px-McGregor_Mountain.jpg)
The North Cascades features some of the most rugged topography in the Cascade Range with craggy peaks and ridges, deep glacial valleys, and granite spires. Geological events occurring many years ago created the diverse topography and drastic elevation changes over the Cascade Range leading to the various climate differences. These climate differences lead to vegetation variety defining the ecoregions in this area.
The history of the formation of the Cascade Mountains dates back millions of years ago to the late Eocene Epoch. With the North American Plate overriding the Pacific Plate, episodes of volcanic igneous activity persisted. In addition, small fragments of the oceanic and continental lithosphere called terranes created the North Cascades about 50 million years ago.
During the Pleistocene period dating back over two million years ago, glaciation advancing and retreating repeatedly scoured the landscape leaving deposits of rock debris. The U-shaped cross section of the river valleys is a result of recent glaciation. Uplift and faulting in combination with glaciation have been the dominant processes which have created the tall peaks and deep valleys of the North Cascades area.
See also
Gallery
-
Sandalee Glacier and McGregor in upper left
(Mount Benzarino in lower half of frame) -
McGregor in upper right
References
- ^ "McGregor Mountain - 8,143' WA". listsofjohn.com. Retrieved 2024-04-08.
- ^ "McGregor Mountain, Washington". Peakbagger.com.
- ^ Beckey, Fred W. Cascade Alpine Guide, Climbing and High Routes. Seattle, WA: Mountaineers Books, 2008. page 289.
- ^ "McGregor Mountain". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved 2020-05-16.
- ^ McGregor Mountain Trail, National Park Service
- ^ Tom Hackenmiller, Ladies of the Lake: Tales of Transportation, Tragedy, and Triumph on Lake Chelan, Point Publishing, 1998, page 50.
- ^ Kruckeberg, Arthur (1991). The Natural History of Puget Sound Country. University of Washington Press.
External links
- McGregor Mountain: Mountain Forecast
- McGregor Mountain weather forecast
- McGregor Mountain Trail National Park Service
- Aerial photo: PBase