Twigs and blades of grass
exist atop the Continental Divide, little more than a dozen miles from my house
as the crow flies, that might split a raindrop in two and send the two halves
to oceans separated by thousands of miles of land. One half will flow down the west slopes of
the mountains and fall into rivers flowing westward to the Pacific Ocean, some
600 miles distant. The other half of the
raindrop will flow down the east slopes and find a way to the Gulf of Mexico
and the Atlantic Ocean, some 3,700 miles to the southwest by way of river
routes. The lofty and unbroken elevations
of the Rocky Mountains (reaching from Mexico all the way through the United
States to Canada) separate the direction of flow for the watersheds on each
side of the range.
There also exists, in
Montana’s Glacier National Park, a mountain named Triple Divide Peak (8,020
ft.) which sheds water into three distinct continental drainages. The water shed from the peak can potentially
flow to the Gulf of Mexico by way of the Missouri; north to The Hudson Bay, by
way of the Saskatchewan River Basin; or to the Pacific by way of the Columbia.
Elevation also plays a
more linear role in separation. The
simple act of driving near a mountain range here in Montana today will reveal
the distinct, and currently receding, snow lines on the higher peaks. Spring ends at the snow line. As spring turns to summer, the wide valleys
tend to dry and the green gradually recedes to higher (cooler and wetter)
elevations. According to the USDA, Montana
supports seven plant hardiness zones—largely based on elevation and weather
alterations created by the presence of mountains.
Some lines of elevation
are firm. The tree line here in Montana,
for example, is somewhere just above 8,000 feet. The climate is simply too harsh above this
elevation to support trees. The higher
elevations tend to be either jumbles of stone and snow or alpine tundra. Taking elevation in the other direction, mountain
huckleberries do not naturally grow in elevations below 2,000 feet.
The death zone begins at
26,000 feet. Life cannot be supported
above this elevation. Essentially,
climbers challenging Everest begin dying once they ascend above this
elevation. The trick is to reach the
top, take a look around, and scramble back down to an elevation below 26,000
feet before death catches them. The air
is far too thin and cold in the death zone.
Additionally, the UV radiation found in sunlight (no longer naturally
filtered by the atmosphere) will blind climbers without protective eyewear. Similar to Icarus in Greek Mythology, we
cannot climb too near the sun without suffering the consequence of death.
Elevation cannot be denied. Standing at my bay window today, I can look
across the valley and see the snow on the upper quarter of the Elkhorn Range. Below, I see the jade-color of spring’s pine
forests. The forests eventually spill
down onto grassy scarps and end there.
The scarps then flow down onto the prairie on which I live—happy to challenge
the huckleberry line and the tree line now and then.
--Mitchell
Hegman
Sources:
New
World Encyclopedia, National
Parks Service, Wikipedia, USDA, U.S. Forest Service, University of Idaho