No record of the next geological stage, which was the Eocene, or earlier part of the Tertiary Age, has been found in the Hills, because they were at that time dry land with gently flowing, shallow streams, and consequently no strata were laid down; but they are supposed, through later evidences, to have had a tropical climate and vegetation, enjoyed by large animals of strange new forms. The volume of fresh water afterwards became so great that immense lakes spread over large portions of the west, one of which occupied most of the region around the Black Hills at the beginning of the Miocene, and animal life was more abundant than ever before and of higher orders, many species being the same as are now in existence. The weather became more and more inclement and as the storms increased the erosion of the Hills also increased, and the rivers changed to torrents with deep channels. Earthquakes are supposed to have occurred and also volcanic eruptions.

The Black Hills were now rising steadily, and as the slope of the streams increased, the channels cut deeper, and the fissures now known as caves had long been filled with water.

The most important of the numerous animals of the Tertiary Age yet discovered in the Hills and surrounding region, are the t.i.tanotherium or Brontotherium, similar to our Hippopotamus, the Oreodon, and a small horse having three toes on each foot. A little later in the same Age the horses were similar to those of the present time and of equal size, which proves that the wild horses of the West were not descended from the few lost by the Spanish Invaders. At this time the first lions, camels, mastodons, and mammoths also appeared. The remains of these animals are so abundant in places as to indicate that they perished in herds that were overwhelmed suddenly by great floods, and many, no doubt, huddled together and perished with cold; for with the beginning of the present age the Hills had reached their highest elevation, the inclement weather increased, and the tropical climate suddenly changed to one extremely cold. It was the beginning of the Glacial Period or Ice Age, when a large portion of the United States is supposed to have been covered by a sheet of ice. The ice is believed to have entered South Dakota from the northeast and its drift across the state limited by a line so closely following the present course of the Missouri River that many of us would be inclined to consider it the western bluff. Beyond this line the ice failed to push its way, but the Hills were subject to heavy rain storms that filled the streams and carried large quant.i.ties of bowlders and other eroded material, both coa.r.s.e and fine, down into the valleys and over the lower hills, where much of the moderately coa.r.s.e can now be seen exposed on the surface, and fine specimens collected without the use of a hammer. The brilliantly colored, striped and mottled agates, and the bright, delicate tints of the quartz crystal, are particularly attractive to the majority of visitors. The beauty of these gaily colored rocks is quite extensively utilized by the inhabitants of the southern and southeastern hills to supply the place of growing plants which are generally denied by the inconvenience of the water supply. The quartzite of the Hills is well crystallized and heavy.

I have one beautiful specimen of the dark Indian red variety through which pa.s.ses a narrow line of pale blue, and the yellow quartzite or jasper sometimes shows dendrite markings. Very great quant.i.ties of agates and jasper, mostly in small pieces, but unlimited variety, are to be seen in portions of the Bad Lands, south of the fork of the Cheyenne River, with an almost equal abundance of baculites and numerous other fossils.

The wide expanse of deep ravines and sharp, barren ridges in the Bad Lands is a unique departure from the usual phases of natural scenery that inspire interest and wonder, but no great admiration, until one soon learns that the law of compensation has been strictly observed. The beauty of vegetation denied those desolate b.u.t.tes and ridges is atoned for by a marvelous abundance of most wonderful crystals of aragonite, calcite, barite and satin spar; each to itself, or two or more combined in beautiful geodes or else arranged in great flat slabs crystallized on both sides of a thin sheet of lime. These slabs are composed of crystals of uniform size and of a pale green tint. But the geodes show some striking combinations of both crystals and colors with an exterior formed like box work, composed of a very heavy dark material said to be a mixture of barium, calcium and iron. The interior may be a bright green or lemon yellow, or perhaps the two in combination, while others yet may be either of these varieties with the addition of flat crystals of almost transparent satin spar. These crystals also occur in ma.s.ses of the same box-like formation rising just so much above the surface of the barren ridge they occupy as to give it the appearance of a prairie dog town. One hill-top over which an abundance of detached crystals, of the palest water-green tint, has been spread, gave the impression of being covered with crushed ice. This transformation from a richly tropical to a marvelously barren region, was accomplished during the time when storms reigned over the Hills and ice ruled the country to the north and east.

The long slender barite crystals of a bright golden brown color are especially beautiful but are generally seen in the specimen stores, as the deposit is confined to limited areas and the few persons familiar with the locations are not over anxious to introduce the general public.

The fossil remains previously referred to are of course only a few of the most important, but it is remarked as a curious and notable fact that among the fossils of the lower orders of life in the Bad Lands, the heads have not been preserved. On account of scarcity of water it is necessary for parties to carry a supply even when they expect to be in the vicinity of the Cheyenne River and probably ford the South fork, as these waters carry in solution a quant.i.ty of alkali that renders them unfit for drinking, although the effects would not be fatal but simply the extreme reverse of pleasant.

No caves have been discovered in the Bad Lands, unless that name be applied to some of the geodes which are really grottoes, they being of sufficient size for a man to stand in. The Black Hills, however, contain some of the most remarkable caves ever yet discovered, of which those of greatest importance are Wind Cave and the three Onyx Caves near Hot Springs, in the southeastern part of the Hills, and Crystal Cave near Piedmont, in the northeast. All of these occur in the Carboniferous Limestone which forms an outer belt around the central ma.s.s or core of the Hills and no doubt, as previously suggested, owes its fissures to earthquakes which preceded or accompanied the porphyry intrusions by which in some localities its strata have been thrown into a vertical position.

CHAPTER IX.

WIND CAVE.

Wind Cave was discovered in 1881 by a hunter named Thomas Bingham, who being weary of a fruitless chase sat down to rest, and was soon startled by the sound of rushing wind on a calm day; and at the same time by a singular hair-raising sensation, as his hat was lifted from his head and thrown high in the air. He is said to have afterwards declared that although frightened nearly out of his wits, he determined to find the cause of his alarm, and on turning slightly discovered a hole about eight by twelve inches in size through which a roaring wind was issuing from the earth. As his hair maintained the aggressive att.i.tude taken, the recovered hat could not be returned to its usual place, so an hour was spent in laying it across the opening and watching its instant projection into upper s.p.a.ce; after which he set out to tell of the wonderful discovery. The announcement, however, was not received seriously and he was a.s.sured of the impossibility of the wind blowing through a hill of solid rock, and his brother explained to him that he had been too self-indulgent and consequently imagined the whole affair.

A protest of total abstinence failed to inspire confidence, but the brother promised to go the next day to see for himself, and did. The hat was again placed over the opening as before, but instead of taking the expected lofty flight, it was drawn in and has never since been seen: the current had reversed. Soon after this the hole was enlarged to eighteen by thirty inches and the cave entered by quite a number of venturesome persons a.s.sisted by a long rope and ample personal courage.

No other improvements were made, and only a short distance was explored, until Mr. J.D. McDonald settled on the property in 1890; since which time he and his sons have explored ninety-seven miles of pa.s.sage and done such extensive work in opening up small pa.s.sages and placing ladders, that it is now possible for visitors to travel long distances with surprising ease and comfort. The measure of distances in the cave is not by the usual guess-work method which has established the short-measure reputation for cave miles, but is done with a fair degree of accuracy by means of the twine used to mark the trail in exploring new pa.s.sages. A careful measurement of the twine has shown it to run nine b.a.l.l.s to the mile with a close average of regularity, so it is the custom to add another mile to the cave record as often as a ninth ball becomes exhausted.

Wind Cave is twelve miles north of Hot Springs by a good road which offers somewhat meager attractions to the artist, but is more liberal towards the geologist, and especially so in fine exposures of the gypsum bearing Red Beds of the Tria.s.sic. Limited patches of it are also exposed in each of the caves, generally carrying small quant.i.ties of selenite, which is crystallized gypsum, or in other words, crystallized sulphate of lime. This brilliant red color is so prominent in portions of the Hills, and attracts so much wondering attention in other well known regions of the West, that it would seem an unpardonable neglect of opportunity should we fail to again quote Prof. Todd for an explanation of the cause of the vivid coloring. Commencing he says: "Newton remarks concerning this:[4] 'A large percentage of peroxide of iron in the red beds, to which they owe their bright red color, bears an interesting relation to the absence of fossils. The material of which sediments are formed is derived, by the various processes of denudation, from the rocks of older land surfaces. Whatever iron they contain is dissolved from the land and transported in a condition of protoxide and some proto salt, such as the carbonate, and the process is facilitated by the presence of carbonic acid in the water. Now iron occurs in these older rocks as protoxide and peroxide, the former of which is soluble and the latter insoluble in water. The peroxide, however, by the action of organic matter, such as is held in solution in boggy waters, may be deprived of a portion of its oxygen and converted into protoxide and thus be rendered soluble. If the iron-bearing water is confined first in a shallow basin and exposed long to the action of the atmosphere the protoxide of iron absorbs the oxygen and is precipitated as an insoluble red peroxide of iron. If, however, plant or animal life be present in sufficient quant.i.ties, this oxidation is prevented. In case but little foreign material, clay or sand, has been brought by the waters, the deposit will be an iron ore. In case large quant.i.ties of foreign material are deposited from the waters at the same time, there will be produced, in the absence of life, a brown or red clay or sandstone, and in its presence a white or light colored formation containing the iron as a carbonate. We reason therefore from the condition in which the iron is found in the red beds, that there could have been little or no life, animal or vegetable, in the water from which it was deposited. The conclusion is strengthened by the fact of the large quant.i.ties of gypsum which are usually derived from the evaporation of saline waters. The degree of saline concentration which the precipitation of gypsum indicates, would be highly inimical to life. The presence of gypsum helps to account for the absence of life, and the absence of life accounts for the brilliant color. The three prominent characteristics of the formation (that is the red beds) are therefore quite in harmony with each other.'" (Geol. Blk. Hills, p. 138.)

Continuing the subject, Professor Todd says: "Accepting this explanation of the striking red color, the question remains as to how these circ.u.mstances, favorable for its formation, were produced.

"This red color is quite common in the whole Rocky Mountain region, not only on the eastern slope of the mountains, but to the various detached members of the system. We must, therefore, look for some extensive condition. If we seek some case in the present, parallel to the one already indicated, we perhaps can find none better than one on the eastern sh.o.r.e of the Caspian Sea, where, because of dry climate and the shallow waters, the deposition of gypsum and salt is now going on. In the gulf known as the Kara Boghaz, which is separated from the Caspian by a narrow strait, the evaporation is so rapid as to produce an almost constant flow from the sea into it. This strait and this gulf give the impression to an unlearned observer that there must be a mysterious subterranean outlet. The water flows in, carrying with it the salt and other soluble minerals. It then evaporates, leaving the salt and minerals behind."

This explanation is calculated to afford particular pleasure to the many visitors to the Garden of the G.o.ds, in Colorado, who seldom receive satisfactory answers to their questions as to the reasons "why." In that much visited spot, however, the great ma.s.s of the deposit has been removed by erosion and the curiously shaped remnants are only such portions as were exceptionally hard and consequently withstood the action of the submerging waters.

Having made a considerable stop on the way to Wind Cave, we will now hurry on, but with good horses and a fine day the drive is one of great pleasure. The road gradually rises to higher ground and soon reaches a point six hundred feet more elevated than Hot Springs, with a charming view of hill and valley distances, and the way then continues over the hill-tops. At one point by the roadside a circle of tent-stones still marks the spot occupied by Sitting Bull for a week or more after the Custer ma.s.sacre, while he camped here and in the security of his commanding position watched the movements of the government troops who were in search of him.

Hot Springs and Buffalo Gap are both included in the wide-spread view.

Beside the road and scattered about in all directions are fine specimens of agates and quartz crystal which seem most beautiful and most abundant on the hills in the immediate vicinity of the cave, the crystals being either rose pink, pale green, yellow, white or colorless.

Arriving at the cave, the entrance is not visible, but between the ravine in which it is located and the road, there is the cave office and small hotel, on the ravine side of which an outer stairway leads down to the cave entrance, over which has been built a log cabin.

On account of the precautions taken for the protection of visitors, accidents are so rare that it might almost be said that none occur.

Every person is required to register before entering the cave and all returning parties are carefully counted, although they are usually unaware of the fact. They are always accompanied by two guides and others are added if the party is large. No one is, on any account, permitted to wander in advance of the head guide or linger behind the one in the rear.

Within the cabin the immediate entrance to the cave is securely closed, and in order that the door may not be forced from its fastenings by the roaring wind which shakes it threateningly, it opens in, instead of out.

This wind suggested the name Wind Cave, and will probably be utilized, at no very distant time, to generate electricity for lighting the cavern.

The wind is strongest at the surface, and a guide goes down first to place lights in sheltered nooks where the force has begun to diminish, about fifty feet below the entrance; and here we light our candles which, if guarded somewhat, are not extinguished unless the current is unusually severe. The balance of the descent of one hundred and fifty-five feet from the surface to the first chamber is easily accomplished.

This would be the least interesting room in the cave if it were not the Bride's Chamber, on account of having once been the scene of a marriage ceremony. But no others are in need of a.s.sistance of such romantic nature, as all are curiously and handsomely decorated, with such a charming variety of deposits, artistically ma.s.sed, combined or contrasted, that every step brings fresh pleasure, and monotony is nowhere.

Pa.s.sing from this room by a long, narrow pa.s.sage, in the walls of which are observed many beautiful little pockets of crystals, attention is presently called to Lincoln's Fireplace, a perfectly natural specimen of the old-fashioned design broadly open in the chimney; doubtless just such an one as Mr. Lincoln's good mother hung the crane in and set the Dutch oven before. A little beyond and on the opposite side of the crevice is Prairie-dog town, not a very extensive town, to be sure, but so true a copy that one unfamiliar with the small animal and his style of architecture would afterwards easily recognize both. At one time his dogship was carried away by a too eager collector, but a letter to the suspected visitor brought him home by the next freight.

The Dutch Clock occupies a position on a shelf near by, and all southern visitors greet the Alligator as a familiar friend, as all of us joyfully meet any acquaintance from home.

A long narrow pa.s.sage, formerly a "tight crawl," but later opened up by heavy blasting, must be traversed before we come to the Snow Ball Room, beautiful with round spots of untinted carbonate of lime, as if fresh soft snow had been thrown by the handful over walls and ceilings, with the additional ornamentation of calcite crystals. In the crevice beyond rises the Church Steeple, diminishing regularly, though roughly, in size, to a height of sixty feet, but not degraded with the little squirming stairway usually seen in Church spires.

The next room is the Post Office, in which we are for the first time introduced to the greatest peculiarity and most abundant formation known to the cave. Being a newly discovered addition to geology it has no scientific name and therefore is simply called box work, because it resembles boxes of many shapes and sizes. The formation of the box work is generally regarded as an unexplained and unexplainable mystery, but a careful study of various portions of the cave shows it in all stages of development and suggests a reasonable theory as to the cause of its origin and variety of development. The volcanic disturbances which have already been discussed as having been responsible for the various uplifts and depressions of the Black Hills region, and also for opening the fissures which gave the cave a beginning, must have supplied the conditions that were necessary to the formation of box work. And these preliminary conditions were merely cracks in the rock. By the violence of earth movement the limestone has been crushed, probably when the land was undergoing depression, prior to the upheaval which opened the great parallel fissures. The varying hardness of the rock, as well as proximity to the surface, would readily account for the difference in size of the fractures, which is from one-half inch to twelve inches; the largest being the most distant from the surface. That this crushing was done before the salt waters retired from the region, which was towards the close of the Cretaceous Age, is sufficiently evident in the fact that portions of the Red Beds show similar fractures with the cracks filled with gypsum, and gypsum, as we have already seen, is a salt water deposit.

After the crushing was done the cracks in the Carboniferous Limestone were filled with water heavily charged with calcium carbonate, taken in solution from the rock, first from pulverized particles, and afterwards by percolation and contact with exposed surfaces. This calcium carbonate was slowly deposited in crystalline form, so that in time the cracks were filled and the crushed rock firmly cemented with calcite seams. But in the meantime the removal of the calcium carbonate had started disintegration of the more exposed portions of the rock, which steadily continuing, finally reduced the porous body between the crystal seams to a soft clay which was gradually dissolved and carried out through small imperfections in the thin crystal sheets, leaving the empty box work as we find it. But where blasting has exposed fresh surfaces, much of the solid limestone carries the box-like sheets of crystal.

The thinnest box work is seen in the upper levels, from which the waters retired soonest, and the heaviest and most beautiful is in the Blue Grotto, on the eighth level where the water remained longest and its diminished volume became most heavily charged. In many places, however, there is another heavy variety known as pop-corn box work, which seems to be an impure lime carbonate not so finely crystallized as the other, but at the time of my visit no explanation had been given of the manner of its deposit; and my own theory that it was not formed under water had nothing to sustain it until, a few weeks later, while visiting Crystal Cave, the work was found in active progress on surfaces occupying every position, and the agent was dripping water. In all cases the original box work has been in thin sheets of calcite, and the heavy varieties are due to later deposits of calcite and aragonite crystals or, pop corn.

The colors are white, yellow, blue and chocolate brown; the last named predominating to a great extent in that portion of the cave most easily traveled by visitors, and forming the ceiling and a part of one wall in the Post Office, where, as has been said before, it first appears. The effect is not dreary as might be imagined, and parties are generally photographed here because one side of the room is white and greatly a.s.sists the flash. This is a smooth, perpendicular wall marking the line of the fissure and showing the strata of the rock in horizontal position whitened with a thin coating of carbonate of lime. All visitors are cordially invited to please themselves in leaving cards, letters or papers in this chamber, which is reserved for that purpose, and to refrain from leaving them in other portions of the cave or defacing the walls with names.

Roe's Misery is a long, narrow pa.s.sage into which, during the early times before its size had been increased by blasting, a large man named Roe crawled to his sorrow. Being larger than the hole he stuck fast, and neither his own efforts nor those of the guides could relieve the situation until a rope was sent for, and having been brought, was securely fastened to his feet, when a long pull and a strong one finally opened the pa.s.sage. It is told that he claimed to have reviewed all the objectionable acts of his life, by which his friends understood that he occupied the motionless position not less than three weeks.

Red Hall is very nearly described by its name and is quite a showy room, with the bright red walls contrasting sharply with their limited ornamentation of pure white carbonate of lime and pearly crystals of calcite.

Off to one side of Red Hall is a beautiful little chamber called Old Maids' Grotto, probably on account of its trim appearance and ideal location. It is so entirely concealed from the view of those pa.s.sing on the public highway, that its existence is not even suspected, until special attention is called to its cosiness, and then it is necessary to mount an acc.u.mulation of great water-rounded rocks in order to obtain convincing evidence of its actual reality. It is a long, narrow room, shut in by a straight wall sufficiently high for rigid seclusion, or protection, without preventing a glimpse of pa.s.sing events.

A break in the description is made here for the purpose of inserting a description, written at the author's request, by Mr. E.L. McDonald. He was generally our special guide. He has chosen to describe the route taken by the majority of visitors and therefore the balance of my observations within those limits are omitted.

All who are familiar with those pa.s.sages and chambers will observe while reading the next chapter that no imaginary attractions are added to the existing facts, but many interesting minor points are missing.

Only such changes are made as were agreed to as the condition on which he would attempt a piece of work so at variance with his usual occupations.

FOOTNOTES:

[4] U.S. Geological Survey. Geology of the Black Hills. Henry Newton, p.

138.

CHAPTER X.

WIND CAVE CONTINUED.

THE FAIR GROUNDS ROUTE.

"At 9:30 in the morning the train bringing health-seekers and tourists arrives at Hot Springs, a beautiful little city nestled in the southernmost foot-hills of the world-reputed Black Hills of South Dakota. The choice of a hotel is soon made, and when located, the new-comers observe the other guests and acquaint themselves with the attractions of the resort. Probably during the day they are approached by the solicitor of the wonderful Wind Cave, who explains that the best way to reach the cave is by means of the coach and four seen at the hotel in the morning, and arrangements are made for the following day.

The next morning, seated in the tally-ho coach with strangers who are soon acquaintances, you start on a beautiful twelve-mile drive to one of nature's most interesting sights.

"Immediately after leaving town you begin to admire the scenery and enjoy the cool, refreshing breezes, wafted from the mountains to the north, down the slopes to the arid plains.

"After climbing a gently sloping 'hog-back' for about eight miles, you are at the top of the divide and one thousand feet higher than Hot Springs, which may be seen on the left. Looking ahead you can see Harney Peak, the highest mountain in the Black Hills district; and on the right you see Buffalo Gap, through which the creek runs that heads at Min-ne-pa-juta Springs. The Indians used to drive buffalo through this gap, hence its name. A small but thriving little town to the eastward takes its name from this Buffalo Gap. From here you begin to go down a gentle and winding incline to the cave, which is reached all too soon.