Why Are There So Many Rivers
in Denali National Park?
The Very Braided East Fork River
|We wake up at daybreak to find a thick coating of ice still on
the tent where the rain had frozen during the night. The first
thing that we hear is the roar of the Toklat River. This is
the river that we'll be hiking near all day today.
Are you are wondering why there are so many
rivers in Denali?
I do, too. Today, we explore and try to find out the answer
to this question.
Breaking Camp on a
Cold Denali Morning.
We crack the
tent door and find that it is still cold outside, below
freezing. While grabbing a quick bite of breakfast, we decide
that to get warm we should start hiking right away. Later, we
can heat up water and have a hot breakfast.
As we scope out our path, our eyes are drawn to the wide, flat
riverbed in front of us. The millions of rocks, glacial
till, that have been swept down from a glacier upstream form a wide
riverbed. Out on that riverbed there are no willow shrubs to
tangle our feet, no swampy wet tundra to bog us down, and no
uneven frost heaves to trip us up. The flat riverbed is
great for hiking on.
As the glacier melts, a river is formed.
Wide River Beds
The glacial till caught in the river's current eventually drops
to the river bed. When enough of these rocks drop in one place,
the river's direction is changed or the river is split into two parts.
Glacial rivers split and change direction over and over and over
until a braided mess is formed.
A River Crossing
Soon, we realize that we are going to have to cross the river
because it bends in close to a cliff and there is no other way over
or around it.
Our Arctic Guide Book states that mornings are great times to
cross rivers because the glacier does not melt as fast during the
cool night. During the day the warm sun melts the glacier more
Getting Ready to Cross One
Braid of the River
|making the river run higher
and faster. We decide that we have to cross before the river gets even
higher with the day's melting glacier ice. The problem is that this
morning the river is already flowing fast. It is swollen
from last night's rains. And it is very cold. Its
gray, silted water flows directly from a nearby glacier and is still
close to freezing.
A cold, cold river crossing.
We also read in our
guidebook that soon, the cold, sunless winter will dry this river's flow from the
glacier down to a trickle. It will dry up until next summer
when the sun gets warm enough to melt the glacier's ice again. That
does not help us now, though.
We have to cross before it gets even higher this
morning. I change into my Tevas and get ready to cross over
first. It is flowing so fast and gets up to my knees on the first
braid of the river and up to my thighs on the second braid. It was
mind-numbingly cold and my feet have an odd combination of numbness
and pain. This crossing was dangerous because the
| river was
flowing so fast. It almost knocked me over. It was cold! So cold that I was completely
numb and not thinking too well. I was near hypothermia.
|So, You Want To Learn
More About Alaska's Glacial Rivers?
a River Without a Bridge