June 19, 1923

Volume II June 19, 1923 Number 2 W. B. Lewis, Superintendent Ansel F. Hall, Chief Naturalist

THE ORIGIN OF YOSEMITE VALLEY.

Prior to 1913 fully fourteen various theories of the origin of Yosemite had been advanced by different scientists. In the interest of proving the facts in the genesis of "The Valley Incomparable" the Sierra Club, acting in the name of the people of California, in that year requested the United States Geological Survey to undertake the ultimate solution of the Yosemite problem. Francois E. Matthes, geologist and topographer, had already completed his masterpiece the Yosemite Valley Special Sheet, a map of quality that has never before or since been equaled. To him fell the task of carrying out the proposed survey that has occupied him and the years since. Two years were spent in mapping the trails of the early glaciers, and with these data in hand it became evident that Yosemite had been subjected to two or more glacial invasions. The findings also brought out the fact that Yosemite Valley was more than 2,000 feet deep before these glaciers ever entered it. Mr. Matthes and his fellow geologists have spent several years' task in the working out of the history of Yosemite -- a story that goes back 50,000,000 years to the upheaval of the Sierra Nevada. The complete story of the formation of Yosemite as proved by these studies is now being printed in a nontechnical bulletin by the Geological Survey, and in a condensed form by Mr. Matthes personally. Both publications should be available for next season. Lectures on the origin of Yosemite Valley are given daily at 10:50 A.M. at the Yosemite Museum. Here, by the aid of a large relief model of the Valley, the geological problems can be easily explained;

YOSEMITE'S FLOWERING SEASON.

One of the most interesting features of the Yosemite National Park is its long flowering season. Approaching the Park by the way of Merced Canyon one crosses the park-line at an altitude of about 2500 feet. At this elevation flowers are blooming profusely by the first of April. The spring season climbs slowly up the slopes and it is not until the middle of June that it

Volume II, No. 2 Page 2 reaches the Yosemite Valley-- 4000 feet elevation. Three thousand feet above the Valley the spring is two months later. Here the meadows are in full bloom during July and August. The alpine gardens reserve their display for the hardy mountaineer who arrives in September to explore the region above timber line. Thus the flower lover might spend six months of continual delight in Yosemite National Park associating with freshly bloomed flowers, at the different elevations.

BAND-TAILED PIGEON'S NEST FOUND.

Those who took advantage of the Nature Guide Service field trip last Tuesday morning were fortunate in observing a pair of Band-tailed Pigeons building their nest in an oak among the cabins of Yosemite Lodge. The male made frequent short trips to near-by trees, selected twigs from the upper branches and hurried back with them to the nesting site. The female received the building material and deftly adjusted and readjusted the twigs until they formed a part of the loosely constructed nest. Such a nest is on exhibit in the natural history room of the Yosemite Museum. Band-tailed pigeons have been threatened with the fate of their near relatives, the Passenger Pigeon, now extinct. Fortunately, both State and Federal government now give full protection to the bird.

SEE THE YOSEMITE VALLEY MODEL.

Before taking any of the road or trail trips the Yosemite visitor should examine closely the ten-foot model of the Valley, which is exhibited in the Yosemite Museum. This intricate scene has been reproduced in miniature from engineering data and is accurate to 1/3 of an inch at every point. More than a year was spent in its construction. The model is built on such a large scale (9 inches to the mile) that one can follow the exact route on any of the roads or trails of the region. Actual views of all scenic features can be obtained by sighting over the various points one expects to visit.

NORTHERN VIOLET-GREEN SWALLOW NESTING IN LEIDIG MEADOW

On one of the Nature Guide field excursions a group watched a female northern violet green swallow gather nesting material on the ground and carry it to an old woodpecker's cavity in a dead tree stub. This is the most beautiful of the swallows, having violet and greenish reflections on the back and a patch of white at the base of the tail on each side. This lover of the forest belt of our mountains not only nests in trees but also in crevices in the cliffs. Although these swallows circle about over the meadows they are not as abundant as are the white-throated swifts which usually fly about high above the Valley floor.

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PORCUPINES IN YOSEMITE VALLEY

A porcupine or "quill pig", not often found on the floor of Yosemite Valley, has recently left his unmistakable mark on certain small yellow pines on the rock talus slopes near Yosemite Lodge. In winter the animal seats himself in some comfortable crotch of a small pine tree and proceeds to devour all of the bark within reach. Should there be a comfortable seat on the opposite side of the tree he is apt to occupy it in turn and thus girdle the trunk and cause the death of the top of the tree. Porcupines do not shoot their barbed spines. An incautious enemy must come in contact with the body or the vigorously lashed tail if he is to suffer.

THE SHOOTING STAR

In the marshy meadows of the Yosemite Valley the Shooting Star (Dodecatheon jeffreyi) is one of the most attractive flowers. It can be seen now in the Sentinel and Curry meadows, but the finest show is to be found in a little meadow on the north side of the Valley near the Iron Spring. Here the flowers are so abundant that the place is often spoken of as "Shooting Star Meadow." The Shooting Star is one of the first spring flowers. This year it is particularly fine, with its large clusters of pink flowers borne on stems two feet tall. The observer at once notes a resemblance to the potted Cyclamen of the florist windows. In fact, the Shooting Star is often called "Wild Cyclamen." The Shooting Star occurs in many parts of California but nowhere are more beautiful specimens found than here in the Yosemite.

SIERRA GROUSE FOUND NESTING AT INSPIRATION POINT.

The "drumming" of the Sierra grouse so commonly heard along the higher trails has for sometime reminded us that the nesting season is on. Parties entering the Valley via Inspiration Point recently reported finding a nest containing eggs. Unfortunately this splendid game bird appears to be rapidly decreasing in numbers in most mountain sections. The additional protection afforded by a national park seems to allow the birds to hold their own in this section for the species is certain to be encountered in the red fir forests of the higher altitudes.

THE "COPPERHEAD"

The attractively colored "chipmunk" to be seen near the hotel at Glacier Point is properly called the Sierra golden-mantled ground squirrel, but is often dubbed "red-headed chipmunk" or "copperhead." He is a common inhabitant of the forested region above the rim, finding shelter in a burrow. The more slender chipmunks are not so vividly colored.

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PACIFIC RATTLER ON EXHIBITION AT MUSEUM.

A small Pacific rattlesnake now graces the reptile room in the Yosemite Museum, where it is attracting great interest. Rattlesnakes are the only poisonous snakes found in California that one need fear and they are distinct enough so that they need not be confused with the non-poisonous ones. Rattlesnakes are not often found in Yosemite for everyone kills them on sight. The danger of being bitten is very slight for this snake does not move about attacking people but usually hunts a safe retreat when approached. One is in much less danger when in the foothill district where rattlers are abundant than in a city or in an automobile but people persist in magnifying the first and minimizing the second. Rattlesnakes should be respected but not feared:

THE INDIAN PINK

The travelers who approach the Yosemite by way of the Big Oak Flat Road are delighted with the brilliant red flowers that grow along the roadside. Masses of these flowers line the edge of the wood. The flower is about an inch across and the fringed petals give it a handsome look. The common name is Indian Pink. The Indian Pink (Silene californica) was very beautiful at El Portal three months ago, but now it is found only at places of higher elevation.

WHITE-HEADED WOODPECKER NESTS AT GLACIER POINT

As in past years those tramping to Glacier Point under instruction of a Nature Guide were rewarded with a visit to a White-headed woodpecker's nest. This uniquely colored mountain woodpecker stirs the interest of everyone who sees it. Its habit of nesting close to the ground affords an unusual opportunity to study nesting habits.

Digitized by Yosemite Online Library Dan Anderson