Geology of the Grand Canyon: De Motte Park.


Its length is about ten miles, its average width about two miles. It is a depressed area in the heart of the plateau and is on every side girt about by more elevated ground rising by strong slopes 300 or 400 feet above its floor. The borders and heights above are densely forest-clad, but not a tree stands within the park itself. Descending into its basin and proceeding southward about two and a half miles, we reach a little spring where we make camp. The distance from the Big Spring to Stewart's Cañon is about 26 miles by trail.

De Motte Park is eminently adapted to be the base of operations in a campaign of geological investigation upon the southern part of the Kaibab. It is a central locality from which we may radiate in any direction to the bounds of the plateau. Here the great bulk of the supplies may be deposited, and from the supply camp we make journeys with light packs for one, two, or three days, as it may suit our convenience, and to it we may return to fit out for another short trip. The circumstances which make the park so advantageous in this respect are worth reciting.

Notwithstanding the open character of the forest there are two difficulties in the way of travel on the Kaibab. The first has already been mentioned, scarcity of water. We know of about a dozen small springs, some of them conveniently located for the purposes of the explorer, others not. There is, however, another source of water supply which will be described presently. The second difficulty is the danger of getting lost and bewildered in the forest. This may seem to be a singular source of danger for an explorer, who of all men is bound to know his exact whereabouts at every step. But if he were to visit the Kaibab with that easy confidence and without a guide he would probably learn a severe lesson in less than a fortnight. The young Mormon herders who range over this region, and who follow a trail with the keen instincts of Indians, and with more than an Indian's intelligence, dread the mazes of the forest until they come to know them. Even the Indians who live and hunt there during the summer and autumn have sad tales about comrades lost when the snows cam early and buried the trails so that they could not be followed. The bewildering character arises from the monotony of the scenery. There are hundreds of hills and gulches, but they all look alike. There are no landmarks except trees, which are worse than none at all. If you enter a ravine for the second time at a point other than that at which you first entered it you would probably fail to recognize it. As with the faces of the Chinese, no conscientious white man would be willing to swear that he had ever seen any particular one before. Yet the riddle of the Kaibab is soon solved, and, once read, all danger is over. If the traveler is lost there is an infallible clew. He must go at once to De Motte Park. But how shall he find the way! If he has reason to [U. S. GEOLOGICAL SURVEY. DEMOTTE PARK. ANNUAL REPORT 1881. PL. XXX.] suppose that he is within a dozen miles of it he has only to enter a main ravine and follow it to its head. This, however, does not apply to the portions of the plateaus which lie more than five miles north of the park. The way may be long, but is easy and sure. A few ravine fade out before reaching the near neighborhood of the park. In that event take the nearest one on the right or left. All of them head upon the summit which looks down into the park. It is necessary, however, to keep to the main ravine and avoid its minor tributaries, and there is a criterion by which it may be distinguished. At the confluence of a lateral ravine the grade of the main ravine is always the less of the two.

Although this may seem to be nothing more than a trival bit of woodcraft, it really illustrates an important fact&the drainage system of a large portion of the Kaibab. The study of this drainage system will shed some light upon the geological history not only of the plateau itself, but of the region adjoining, and of the Grand Cañon.

The thought which must be predominant in the mind of one who for the first time enters the Kaibab is of the Grand Cañ. The fame of its grandeur is world-wide, and desire to see it as it is grows stronger the nearer he approaches to it. This longing must be at least tempered if not wholly satisfied before the mind is in the humor to contemplate anything else. Our first expedition, then shall be to the brink of the great abyss.

As the sun is rising and before his beams have penetrated to the bottom of the park we are on the way. On either hand is the forest, covering the slopes and the heights above, but ending suddenly at the foot of every incline. Before us to the southward stretches the open field with hardly an undulation. Six or seven miles away we can see the sylvan walls approach each other, leaving a narrow gateway between the tall spruces where the surface of the ground for a moment is sharply projected against the sky. The scene is, on the whole, a very attractive one. There is a great wealth of vegetation, somber indeed, and monotonous, but the darkness of the tone is suggestive of depth and richness of color. The only alleviating contrast is between the smooth expanse of the park and the myriads of sharp spikes which terminate the tree tops. The spirit of the scence is a calm, serene, and gente one, touched with a tinge of solemnity and melancholy.

About a mile from camp we came upon an object worthy of attention. It is rather a deep depression in the earth about 200 feet across and very nearly circular. Within it is a large pool of water. Its depth below the valley floor may be about 40 feet, and the depth of the water 5 or 6 feet in the middle. It is a fair specimen of a frequent occurrence upon the Kaibab. I have never seen them elsewhere, and the explanation is difficult. The interest lies in the mystery of their origin. In every day's ride we usually find three or four of them and sometimes more. Some of them contain water, but the majority do not. Some hold water throughout the year, some only in the early summer or until autumn. They vary in size and depth very considerably. Some are as narrow as 20 feet; some are 300 to 400 feet across. The depths vary from a yard or two to a hundred feet. The form is crater like-always approximately circular. They do not appear to occur under any special set of conditions. They are found as often upon the platforms as in the valleys and are not uncommon upon the slopes of the ravines. In a few instances traces may be seen of rain gullies or washes leading into them, but not often, and none have ever been noted leading out of them. Whatever running water may enter them sinks within their basins; but it is certain that many of them rarely receive any running water. In the cases of those which do the wonder is that they do not soon fill up with sand and silt, for the water generated by heavy rain storms or by melting snows, when sufficient in volume to run a stream, is always thick with mud. The scarcity of running water on the Kaibab has been mentioned. Yet the precipitation is comparatively great and the evaporation small. It is apparent that all the water which falls upon its vast expanse, with the exception of a slight percentage evaporated, must sink into the earth, where it is doubtless gathered in subterranean drainage channels which open in the profound depths of the great amphitheaters of the Grand Cañon. In those depths are large creeks of perennial water issuing from the openings of those underground passages. This implies a system of subterranean rivulets, but it is not more wonderful than the endless caverns in the limestones of Kentucky and Indiana, and it is probably not upon so large a scale nor so greatly ramified. It also argues a high degree of permeability both in the upper strata and in the overmantling soil. The water sifts through them as easily as through sand, and rarely gathers into streams even in the copious showers or most rapid melting of the snow. Whether these “lagoons“ and “sink-holes,“ as we termed them, are the openings of pipes leading down into the subterranean rivers and kept open by a gradual solution of the limestone, it is difficult to say. There are some difficulties in the way of this theory.

Moving rapidly southward, at length we reach the Sylvan Gate at the lower end. Passing through we immediately find ourselves at the head of a second park very similar to De Motte's but smaller, having a length of nearly three miles. It is named Little De Motte Park, and the Sylvan Gate occupies a divide between the two. It contains a large lagoon holding stagnant water. There is a chain of these parks reaching from the northern end of De Motte's southward, a distance of 25 miles, separated only by necks of forest.

Our first objective point is a spring situated in one of the large ravines which head in the heights overlooking these two parks. Without some foreknowledge of the way to reach it, or without a guide, it would be impossible to find it, and the same is true of any other spring on the summit, but with this foreknowledge we seek the southwestern border of Little De Motte and enter the timber. During half an hour there is a miserable struggle with fallen trees and thick set branches of spruce and aspen, but at length the heights are gained, and we descend into a shallow ravine where the way is once more open. The winding glade with smooth bottom richly carpeted with long green grass, aglow with myriads of beautiful blossoms is before us, and the tall trees are on either hand. Soon it leads into a larger one, and this into another, until at last the main ravine is reached. Very sweet and touching now are the influences of nature. The balmy air, the dark and somber spruces, the pale green aspens, the golden shafts of sunlight shot through their foliage, the velvet sward-surely this is the home of the woodland nymphs, and at every turn of the way we can fancy we are about to see them flying at our approach, or peeping at us from the flowery banks.

By half-past ten the spring is reached. Next to the Big Spring, in Stewart's Cañ, it is the largest on the summit of the plateau. Here, too, is the only semblance of running water, for the stream flows a little more than half a mile before it sinks. The water is cold and delicious. It has a faint whitish cast like that which would be produced by putting a drop or two of milk into a bucket or pure water. I presume it is caused by a fine precipitate of lime. We called it the “Milk Spring.“ Pausing here for a hasty lunch, and to fill the kegs (for to-night we may make a “dry“ camp), we push on. We climb out of the ravine, and in fact we only came here to obtain water, as it is the only place near to the point of destination at which water can be procured. The route now becomes more rugged, leading across ravines and over intervening ridges, crossing the grain of the country, so to speak. But it is not difficult, for the pines have taken place of the spruces, and where the pines predominate the forest is very open. For eight miles from the Milk Spring we continue to cross hills and valleys, then follow a low swale shaded by giant pines with trunks three to four feet in thickness. The banks are a parterre of flowers. On yonder hillside, beneath one of these kingly trees, is a spot which seems to glow with an unwonted wealth of floral beauty. It is scarcely a hundred yards distant; let us pluck a bouquet from it. We ride up the slope.

The earth suddenly sinks at our feet to illimitable depths. In an instant, in the twinkling of an eye, the awful scene is before us.