"OH, Ranger, Ranger!"
The ranger paused in his talk to a group of
Sagebrushers gathered at the upper end of Yosemite Valley.
"May I ask a question?"
"Yes ma'am," said the ranger, with a twinkle. "Ask me
a hard one."
"Where is the other half of Half Dome?"
Everybody laughed but the ranger.
"Well, it's a long story," began the Old-Timer. "But
I can tell you. It all happened a long time ago and it is just theory,
but so far as I can learn it is as near the truth as anybody has been
able to come. Nature leaves her notes to account for everything that has
happened in the wilderness, but sometimes it is hard to read them.
"Do you see that other dome up there, the round one,
opposite Half Dome? It is known as North Dome, the perfect dome. Half
Dome once looked like that, only much larger. The domes are peculiar to
this country. They are solid granite, pushed up through the softer rock.
They peel off in layers, like enormous onions, because of the alternate
action of the heat and cold on the rock.
"The other half of Half Dome was scraped away by the
glaciers. What happened was this. When the glaciers came in contact with
the walls of Yosemite, the rock contracted under the extreme cold. That
cracked enormous pieces loose and they were slowly borne away by the
glaciers. Half of Half Dome was shaved off the mountain, cracked up, and
pushed away by the ice. It is scattered in boulders down the Merced
The ranger paused for the next "hard one." It was not
long in coming.
"How high is Half Dome?" asked a Sagebrusher.
"It towers about a mile above where we are sitting,"
"Do you mean to say that a glacier could carry away
half of a mountain a mile high?"
"That is the idea, sir. As a matter of fact, it
probably took two glaciers to do the work. During the Ice Age, one mass
of ice pushed down Tenaya Canyon and became wedged between Half Dome and
North Dome. It finally burst through and met head-on with the other
glacier slowly moving down the Merced River Canyon. The two of them
churned around with billions of tons of weight behind them and finally
plucked and scraped at the cliffs until they carved the present walls of
"You can find a record of what happened on those
walls up there. If you look closely, you will see spots where the cliffs
have been polished as smooth as the cornerstone of a First National
Bank. Granite does not crack so smooth naturally. The glaciers, scraping
away at the sides of the mountain, polished the rock. That is one means
used by Nature to leave her notes for men to puzzle out a million years
later. Near Tenaya Lake and again near Merced Lake are perfect examples
of glacier polish on the cliffs.
"Here in Yosemite Valley, the big job of the glaciers
was to shape Yosemite Valley. Streams had already carved a deep gorge,
but the glaciers made it wider. When they melted, the gorge became a
lake. The streams next dumped sediment into the lake and it became a
valley. You can see the same process happening over again, on a much
smaller scale, at Mirror Lake. There the streams are now filling up the
lake with fine silt. Glacier Point, thirty-two hundred feet above the
valley, was left suspended by the glaciers when they melted. One of
Nature's little quips was to leave a great rock suspended over the
cliff, almost half of it projecting over the rim. That is known as
All of the national parks abound in strange phenomena
of Nature. These marvels were the motive for setting aside the area as a
national park. Dudes and Sagebrushers are not satisfied to come and look
at beautiful scenery without knowing why it is there, what happened to
make it, and if it will always look that way. Some of the answers to
their questions are the solutions to the riddles of the universe.
The story of the national parks, from a natural
history point of view, is an interesting one. In the early days many
fakes were perpetrated upon the unsuspecting visitor by guides
ill-trained to talk of the wonders of Nature. Often the true answer to a
question was not known. So the guide told the Dude that half of Half
Dome was shaken down in a great earthquake. To give visitors the true
answers to their questions, as well as they can be read from Nature's
notes, a staff of ranger naturalists is found in each of the parks. The
ranger naturalist's business is to study the mountains, the glaciers,
the forests, the animals, the streams, and the other offspring of the
The nature-guide idea was first undertaken a great
many years ago. Dr. H. S. Conard, of Grinnell College, Iowa, former head
ranger naturalist of Yellowstone, is the third generation of nature
teachers who have taken students and friends afield to study the secrets
of the hills and forests. The first excursions into the national parks
were conducted by men of scientific training, often college professors
and teachers. Later, when travel increased, it was difficult to find
enough men adequately trained to talk of the parks' wonders
authoritatively. Enos A. Mills, of Rocky Mountain Park, and Dr. Harold
C. Bryant, of the University of California, who later became assistant
director of the National Park service in charge of the Ranger Naturalist
forces, and who is Superintendent of the Grand Canyon, were pioneers in
the movement to train ranger naturalists.
The regular rangers, though not scientifically
trained as a rule, have made themselves reliable practical naturalists
to cope with the barrage of inquiries which they are sure to meet each
summer. Long experience has taught them never to laugh at any question,
albeit foolish. "When do the geysers freeze over?" The Yellowstone
ranger hears that one often, and in the old days he used to reply, "Oh,
we freeze them over when we need them for skating rinks." But anyone who
stops to think, knows that the geysers do not freeze over. So the ranger
answers all questions seriously. There is something of the explorer in
every person. When he has discovered a petrified tree, he wants to know
how wood came to turn to stone, how long ago it happened. It makes the
visit to the petrified tree doubly interesting to learn that the wood
did not turn to stone but that the grain of the tree, decaying, was
replaced by silica from the water, that it happened twenty-five thousand
years ago, and that no eruption has taken place in that great span
of years to destroy the relic of the last of the earth's upheavals.
(From the Stanford University Press
Recognizing the educational possibilities of this
interest in the natural phenomena of the parks, the National Park
Service aims to keep at least one ranger naturalist in each park. In the
larger parks a considerable staff is maintained, directed by a head
naturalist who is also in charge of the park museum. In Yosemite,
several ranger naturalists are on duty on the floor of Yosemite Valley,
one at Glacier Point, and at times others are stationed at the Big
Trees, Tuolumne Meadows, and other points where Dudes and Sagebrushers
In most of the parks, the ranger naturalists have
prepared exhibits illustrating the phenomena of the major natural
wonders. For example, the whole history of the Yosemite region, from its
formation by the ancient upheavals of the earth through the eons of the
glacial carvings to its present status, including the living conditions
of the Indians, the coming of the whites, and the early stagecoach
days, is pictured by means of exhibits in the fine, new fireproof
museum, the gift of the Laura Spelman Rockefeller Memorial
(From the Stanford University Press
Following the excursion through the museum, the
visitor is ready for the walking trips with the ranger naturalists to see
and study Nature's notes just as the scientists themselves have found
them and from them pieced together what is known of the story of the
Returning, for the moment, to the ranger naturalist
and his party at the upper end of Yosemite Valley, one of the party is
saying, "I wish I could see a glacier at work!"
"You can do that, ma'am, if you can stay over a few
days. Take the trip up to Tuolumne Meadows and join a horseback party up
to Lyell Glacier. That is one of our best small living glaciers. It is
hardly big enough to tackle a job like carving Yosemite Valley, but it
is grinding away at the side of Mount Lyell, the highest peak in the
park. You can see the glacier dragging down boulders from the side of
the mountain and breaking them up or dumping them into upper Lyell Fork,
where the Tuolumne River starts. Lyell Glacier only moves a few feet
each summer. If you selected a boulder at the top of the glacier to
watch, it would probably take a hundred years or so to get it down to
the bottom of the glacier. Glaciers are slow, but they are sure.
"Of course, if you want to see some fast-working
glaciers, you might stop off in Mount Rainier National Park. The
mountain is farther north and is steeper, also the climate is more
severe and much more snow falls in winter. Glaciers move faster because
there is more ice behind them to make pressure. Some of those glaciers
move along fifty or sixty feet a year. Most of the movement is in the
summer time when the ice is cracking and grinding more rapidly. The
Mount Rainier glaciers are faster workers than the Yosemite glaciers.
They carry so much rock and earth that the ice is dark, almost black, in
color. However, an industrious glacier has its disadvantages. The Mount
Rainier glaciers scoop up many rocks from the mountain side and grind
them together as they slide down the slope, making a fine cement-like
powder, which when deposited in the streams, gives them a gray, milky
color. This is called glacier milk. Sometimes it is called rock flour.
It is interesting, but bad for the fishing. Mount Rainier contains some
of the greatest glaciers in the world.
"There are two kinds of mountains, ma'am, those that
are pushed up, and those that are piled up. This mountain range on which
we are standing, the Sierra Nevada, was pushed up. It is tilted, the
eastern edge of the uplift being from twelve to fourteen thousand feet
above the sea and from five to eight thousand feet above the territory
immediately surrounding it. The western edge is buried beneath the
silt of the San Joaquin Valley. Its slope on the western side is so
gradual that if a highway could be built from the San Joaquin to the summit
of Mount Lyell in a direct line, the grade would be but two per
cent. Yet the Sierra Nevada is considered one of the most formidable
mountain barriers on the face of the earth. It is that because of the
canyons which streams and glaciers have cut in it. On the eastern slope,
the tilt is almost perpendicular. It is said that the Sierra Nevada is a
single mountain four hundred miles long and eighty miles wide, the
biggest mass of granite in the world. John Muir tells of an earthquake
in 1872 which raised the Sierra Nevada thirty-two feet. This was a
tremendous upheaval, but you can imagine how puny it must have been
compared to the original movements which pushed the whole mountain,
eighty miles wide and four hundred miles long, out of the earth.
"Mount Rainier, on the other hand, is an example of a
mountain that was piled up. They say that the whole state of Washington,
which Mount Rainier dominates, was a level plain or else it was under
the sea. It's hard to tell what was under a mountain originally. A
volcano starts blowing lava and rocks and ashes. It keeps piling up and
piling up and piling up some more, perhaps for a million years. Finally,
Mount Rainier was built up by lava outpourings to a height of almost
three miles. Then the volcano quit working. Layer after layer of snow
fell on the mountain as it cooled off. It packed into the crater and
became ice. The ice expanded and contracted, as the weather changed,
cracking off part of the crater. The ice flowed down the mountain side.
Yes, ice can flow. It isn't as solid as it looks, and it will flow when
there is enough pressure behind it.
"Ever since they started flowing down the sides of
Mount Rainier, the glaciers have been grinding down that great mountain.
They have probably taken two thousand feet off the top of Mount Rainier
in the last million years. In another ten million years there probably
won't be much to look at on Mount Rainier. That's one problem that
worries the rangers. But the only thing that can save the situation is
another volcano and the only national park in which we have a steadily
working volcano, Mauna Loa, is in the Hawaiian Islands. We have a live
volcano in Lassen Volcanic National Park, but it is lazy and works but
"While we are on the subject of mountains, I want to
call your attention to Crater Lake. Where the lake now stands there was
once a great mountain which a volcano was piling higher and higher.
Finally it collapsed inside itself. Mount Mazama, it is called,
posthumously. Nobody ever saw it, of course, because this all happened a
million years ago, more or less. It must have been a whopping big
mountain, at least 14,000 feet high, for when the whole peak caved in it
left a hole seven miles in diameter and many thousand feet deep. The
deep blue color of Crater Lake has never been explained. A curious
feature of this beautiful lake is that, though there is no outlet for
the water, it is fresh. That is probably because no streams flow into
it, the lake being located on a mountain top. Its waters come from
rainfall and melting snows that fall into the lake. There is just about
enough of this water to counteract the sun's evaporation."
(From the Stanford University Press
"But we started to talk about mountains, didn't we?
It is difficult to stick to the subject. The mountains seem to be
connected in some way with everything. Either they supply the water, or
the wood, or the coal, or the mineral, or the scenery, or the plants, or
the animals. When you stop to think about it, you can understand why we
rangers feel there is nothing like the mountains anywhere in the world.
And for nice, friendly, busy, obliging mountains, the kind you want to
live with day in and day out, there are none like the mountains of the
national parks. Every superintendent and every ranger feels that the
mountains of his particular park are the best in the world. He would
stack his mountains up against any other mountains any day of the year.
They might not be so high or so broad or so hard as certain others, but
they are superior in some way, and that is what counts."
The mountains seem to be connected in some way with
everything. Either they supply the water, or the wood, or the coal, or
the mineral, or the scenery, or the plants, or the animals. Build a
mountain and then tear it down! That seems to be Nature's whimsical way
of working. The Rocky Mountains were once the bottom of a shallow sea.
The rangers can take the visitor out in the Yellowstone and show him
fossil sea fish and shells. On top of the sea shells he will find a
sandstone deposit, the remains of deposits of an ancient lake. On top
of that he may find a petrified forest. The forest may be covered with
volcanic mud or ash. Then more sandstone; then gravel, the deposit of a
river. In one part of the park they know of twelve forests, buried one
on top of the other, volcanic mud deposits between them. Eons passed
while these forests were growing, each above the tallest tops of its
In Yellowstone are found several of these petrified
forest areas. Lava and ashes destroyed the trees, mud covered them up
and provided silica, which replaced the wood cells, preserving for all
time the grain of the wood. The preservation of the rings of these
ancient trees is of the greatest importance in piecing together the
story of the earth. For a long time scientists thought that a large, fat
ring indicated a moist, warm year, and that a thin ring indicated a
year of drought. It is definitely established that these rings do
contain the secrets of climatic records in prehistoric years. In the
great redwoods of Sequoia and Yosemite parks, some of which have fallen
in recent years, naturalists have traced by means of rings the weather
records for the past three or four thousand years. Now if they can
connect the record of the rings of the sequoias in their ancient youth
with that of the petrified big trees in other parks and monuments, it
may be possible to trace the weather report back to the time of the
Garden of Eden!
Nature leaves her notes in unexpected places!
(From the Stanford University Press
The Carnegie Institution, under the great scientist,
teacher, and executive, Dr. John C. Merriam, is conducting extremely
interesting investigations of tree rings. Dr. Ellsworth Huntington has
traced back climatic conditions for thousands of years already. Other
scientists, working the archaeologists and ethnologists, have studied
tree rings in wood found in cliff dwellings and other prehistoric
structures and have traced human migrations, age of buildings, progress
of forgotten people, and other important data.