Fig. 2.—Ground plan of Wood Canyon Ruin.
The so-called Butte Ruin, situated in Lost Canyon, 5 miles east of Dolores, belongs to the circular type. It crowns a low elevation, steep on the west side, sloping more gradually on the east, and surrounded by cultivated fields. The view from its top looking toward Ute Mountain and the Mesa Verde plateau is particularly extensive. The butte is forested by a few spruces growing at the base and extending up the sides, which are replaced at the summit by a thick growth of sage and other bushes which cover the mound, rendering it difficult to make out the ground plan of the ruin on its top.
From what appears on the surface it would seem that this ruin was a circular or semicircular building about 60 feet in diameter, the walls rising about 10 feet high. Like other circular mounds it shows a well-marked depression in the middle, from which radiate walls or indications of walled compartments. Like the majority of the buildings of the circular form, the walls on one side have fallen, suggesting that a low straight wall, possibly with rectangular rooms, was annexed to this side.
In the neighborhood of Butte Ruin there is another hill crowned with a pile of stones, probably a round building of smaller size and with more dilapidated walls. Old cedar beams project in places out of the mounds.
The cliff-houses below the largest of these mounds show well-made walls with a few rafters and beams. There are pictographs on the cliff a short distance away.
This ruin crowns a low hill about 3 miles south of Dolores (fig. 3). The form of the mound is semicircular with a depression in the middle around which can be traced radiating partitions suggesting compartments. Its outer wall on the south side, as in so many other examples of this type, has fallen, and the indications are that here the wall was straight, or like that on the south side of Horseshoe Ruin.
The author’s attention was first called to this ruin by Mr. Gordon Parker, supervisor of the Montezuma Forest Reserve, it having been discovered by Mr. J. W. Emerson, one of his rangers. The circular or semicircular form (fig. 4) of the mound indicates at once that it does not belong to the same type as Far View House; the central depression is surrounded by a series of compartments separated by radiating walls like the circular ruins in the pueblo region to the south. Mr. Emerson’s report, which follows, points out the main features of this remarkable ruin.[31]
Fig. 3.—Metes and bounds of Emerson Ruin. (After Emerson.)
In August, 1916, I visited Mesa Verde National Park. While there Doctor Fewkes inquired in regard to ruins in the vicinity of the Big Bend of the Dolores River. He informed me that the log of two old Spanish explorers of 1775 described a ruin near the bend of the Dolores River as of great value.
Later, during October, 1916, I visited a number of ruins in this vicinity, including the one which (for the want of a better name) I have mapped and named Sun Dial Palace. Later, last fall, I again visited these ruins with Mr. R. W. Williamson, of Dolores, Colorado.
On July 5, 1917, I again visited these ruins, which I have designated as Reservoir Group and Sun Dial Palace.[32] For location and status of land on which they lie see map of sec. 17, T. 37 N., R. 15 W., N. M. P. M. (fig. 3).
While examining Sun Dial Palace I noted the “D-shaped construction, also that the south wall of the building ran due east and west.” Also please note the regularity of wall bearings from the approximate center of the elliptical center chamber. I also noted that a shadow cast by the sun apparently coincides with some of these walls at different hours during the day. This last gave suggestion to the name. Also please note that the first tier of rooms around the middle chamber does not show a complete set of bearings but seems to suggest that these regular bearings were obtained from observation and study of a master builder. The result of his study was built as the next circular room tier was added. The two missing rooms on the western side of the building seem to suggest that this building was never completed, and also bear out my theory of an outward building of room tiers from the middle chamber.
On the ground this building is fully completed on the south side and forms a due east and west line. An error in mapping the elliptical middle chamber has given the south side an incomplete appearance.
I believe that the excavation and study of this ruin will recall something of value, as Father Escalante wrote in his log in 1775.
Respectfully submitted.
Fig. 4.—Schematic ground plan of Emerson Ruin. (After Emerson.)
A personal examination of the remains of this building leads the author to the conclusion that while it belongs to the circular group, with a ground plan resembling Horseshoe House, and while the central part had a wall completely circular, the outer concentric curved walls did not complete their course on the south side, but ended in straight walls comparable with the partitions separating compartments. The author identifies another ruin as that mentioned by the Catholic fathers in 1775.
The name Escalante Ruin, given to the first ruin recorded by a white man in Colorado, is situated about 3 miles from Dolores on top of a low hill to the right of the Monticello Road, just beyond where it diverges from the road to Cortez. The outline of the pile of stones suggests a D-shaped or semicircular house with a central depression surrounded by rooms separated by radiating partitions. The wall on the south or east sides was probably straight, rendering the form not greatly unlike the other ruins on hilltops in the neighborhood of Dolores.
This is supposed to be the ruin to which reference is made in the following quotation from an article in Science:[33]
“There is in the Congressional Library, among the documents collected by Peter Force, a manuscript diary of early exploration in New Mexico, Colorado, and Utah, dated 1776, written by two Catholic priests, Father Silvester Velez Escalante and Father Francisco Atanacio Dominguez. This diary is valuable to students of archeology, as it contains the first reference to a prehistoric ruin in the confines of the present State of Colorado, although the mention is too brief for positive identification of the ruin.[34] While the context indicates its approximate site, there are at this place at least two large ruins, either of which might be that referred to. I have no doubt which one of these two ruins was indicated by these early explorers, but my interest in this ruin is both archeological and historical. Our knowledge of the structure of these ruins is at the present day almost as imperfect as it was a century and a half ago.
“The route followed by the writers of the diary was possibly an Indian pathway, and is now called the Old Spanish Trail. After entering Colorado it ran from near the present site of Mancos to the Dolores. On the fourteenth day from Santa Fe, we find the following entry: ‘En la vanda austral del Vio [Rio] sobre un alto, huvo anti-quam (te) una Poblacion pequeña, de la misma forma qᵉ las de los Indios el Nuevo Mexico, segun manifieran las Ruinas qᵉ de invento registramos.’
“By tracing the trip day by day, up to that time, it appears that the ruin referred to by these early fathers was situated somewhere near the bend of the Dolores River, or not far from the present town Dolores, Colo. The above quotation indicates that the ruin was a small settlement, and situated on a hill, on the south side of the river or trail, but it did not differ greatly from the ruined settlements of the Indians of New Mexico with which the writers were familiar, and had already described.”
There are numerous cliff-houses in this district, but while, as a rule, they are much smaller than the magnificent examples in the Mesa Verde, they are built on the same architectural lines as their more pretentious relatives. Both large and small have circular subterranean kivas, similarly constructed to those of Spruce-tree House, and have mural pilasters (to support a vaulted roof, now destroyed), ventilators, and deflectors.
There are also many rooms in cliffs, possibly used for storage or for some other unknown purposes, but too small for habitations. It is significant that these are identical so far as their size is concerned with the “ledge houses,” near Spruce-tree House, indicating similar or identical uses.
The kivas of cliff-dwellings of size in the region considered have the same structural features as those of adjacent ruins, but very little resemblance, save in site, to those of cliff-dwellings in southern Arizona, as in the Sierra Ancha or Verde Valley, the structure of which resembles adjacent pueblos.
The absence in the McElmo region of very large cliff-houses is due partly but not wholly to geological conditions, the immense caves of the Mesa Verde not being duplicated in the tributaries of the McElmo; but wherever caverns do occur, as in Sand Canyon, we commonly find diminutive representatives. While differences in geological features may account for the size of these prehistoric buildings, the nature of the site or its size is not all important.[35]
Here and there one sees from the road through the McElmo Canyon a few small cliff-houses, and if he penetrates some of the tributaries, he finds many others. The canyon is dominated by the Ute Mountain on the south, but on the north are numerous eroded cliffs in which are many caves affording good opportunities for the construction of cliff-houses.
These buildings do not differ save in size from the cliff-houses of the Mesa Verde. Their kivas resemble the vaulted variety and the masonry is identical.
Although the existence of cliff-dwellings in the tributaries of the McElmo has long been known, the characteristic circular kivas which occur in the Mesa Verde had not been recognized previous to the present report.
The relative age of the pueblos and great towers and the same structures in caves can not be decided by the data at hand, but the indications are that they were contemporary.
On account of the similarity in structure of the McElmo cliff-dwellings to those on Mesa Verde, only a few examples from the former region are here considered. It may be worthy of note that while McElmo cliff-dwellings are generally accompanied by large open-air pueblos and towers or great houses on the cliffs above, in the Mesa Verde open-air buildings[36] are generally situated some distance from the cliff-dwellings.
Several small cliff-houses occur in Sand Canyon, one of the northern tributaries of the McElmo. Stone Arch House, here figured (pl. 6, a), so-called from the eroded cliff (pl. 4, b) near by. It is situated in the cliff, about a mile from where the canyon enters the McElmo Canyon near Battle Rock. Abundant piñon trees and a few scrubby cedars grow in the low mounds of the talus below the ruin, near which, on top of a neighboring rock pinnacle, still stand the well-constructed walls of a small house (pl. 4, a).
The formerly unnamed cliff-house shown in plate 8[37] is one of the best preserved in Sand Canyon. It consists of an upper and a lower house, the former situated far back in the cave, the latter on a projecting terrace below. Unfortunately it is impossible to introduce an extended description of this building as it was not entered by the author’s party, but from a distance the walls exhibit fine masonry. It is unique in having double buildings on different levels, an arrangement not rare in a few examples of cliff-dwellings on the Mesa Verde. As shown in plate 8, the character of the rock on which the lower house stands is harder than that above in which the cave has been eroded. The upper house is wholly protected by the roof[38] of the cave and occupies its entire floor. The lower house shows from a distance at least two rooms, the front wall of one having fallen.
From a distance the walls of both the lower and the upper house seem to be well preserved, although many of the component stones have fallen to the base of the cliff.
One of the cliffs bordering Sand Canyon has an inaccessible cave in which is an artificial platform or lookout shown in plate 7, a. Although this structure is not as well preserved as the scaffold in the neighborhood of Scaffold House in Laguna (Sosi) Canyon, on the Navaho National Monument, it seems to have had a similar purpose. It is constructed of logs reaching from one side of the cave to the other supporting a floor of flat stones and adobe. Its elevated situation would necessitate for entrance either holes cut in the cliffs or ladders.
In subsequent pages the author will describe a ruin called the Unit type House, situated in the open on the north rim of Square Tower Canyon. A similar type of unit type house is found in a cave in Sand Canyon. The reader’s attention may first be called to the definition of a unit type, which is a building composed of a circular kiva, with mural banquettes and pedestals supporting a vaulted roof, with ventilator, reflector, and generally a ceremonial opening near a central fire hole in the floor. This kiva (fig. 5) is generally embedded in or surrounded by rectangular rooms. The single-unit type has one kiva with several surrounding rooms; the so-called pure type is composed of these units united.
Fig. 5.—Ground plan of Unit type House in cave.
In an almost inaccessible cave (pl. 5, b) in Sand Canyon a few miles from the McElmo road near the scaffold already mentioned there is a cliff ruin, so far as known the first described single-unit house in a cave. It covers the whole floor of the cave (fig. 5) and its walls are considerably dilapidated, but the kiva shows this instructive condition: The walls are double, one inside the other, with two sets of pedestals, the outer of which are very much blackened with smoke of constant fires; the inner fresh and untarnished, evidently of late construction. A similar double-walled kiva known as “Kiva A” exists in Spruce-tree House, as described in the author’s account of that ruin.[39] On the perpendicular wall of the precipice at the right hand of the ruin in the cave above mentioned are several pictographs shown in plate 7, c.
The rectangular rooms about the kiva are in places excavated out of the cliffs, but show standing walls on the front. These were not, however, constructed with the same care as those of the kiva.
The cliff-house in Hackberry Canyon (pl. 9, a) is one of the most instructive. It lies below Horseshoe House and appears to be a second example of a unit type kiva and surrounding rooms.
The cliff-dwelling in Ruin Canyon[40] visible across the canyon from the Old Bluff City Road is well preserved. On the rim of the canyon are piles of stone indicating a very large pueblo, with surface circular depressions indicating unit type houses.
Lost Canyon, a southern tributary of the Dolores River, contains instructive cliff-houses to which my attention was called by Mr. Gordon Parker, superintendent of the Montezuma Forest Reserve, who has kindly allowed me to use the accompanying photographs. This cliff-house (pl. 10, a, b) belongs to the true Mesa Verde type and shows comparatively good preservation of its walls, some of the beams being in place. It is most easily approached from Mancos.
There are small cliff-houses in the same canyon not far from Dolores, but these are smaller and their walls very poorly preserved.
An interesting feature of these cliff-houses in Lost Canyon is that they mark the northern horizon of cliff-dwellings of the Mesa Verde type, having kivas similarly constructed.
Great houses and towers differ from pueblos of the pure type but may often be combined with them, forming composite houses arranged in clusters called villages. Castles and towers may be isolated structures without additional chambers, or may have many annexed rooms which are rectangular, round, or semicircular in form. Semicircular towers surrounded by concentric curved walls connected by radial partitions forming compartments are shown in Horseshoe Ruin, to which attention has been called in preceding pages, and possibly in the circular or semicircular ruins on hilltops near Dolores.
The masonry of the great house and tower type (pl. 11, a, b) varies in excellence, not only in different examples but also in different portions of the same building. Some of the walls contain some of the best-constructed masonry north of Mexico; others (see pl. 6, b) are crudely made. In the Great House of the Holly group, where the walls show superior construction, the lowest courses of rock are larger than those above, but in Hovenweep Castle small stones are found below those of larger size; the Round Tower in McLean Basin shows small and large stones introduced for ornamentation.
The ambitious constructors of several towers have built the foundations of these towers on bowlders sloping at a considerable angle, and it is a source of wonder that these walls have stood for so many years without sliding from their bases. Although so well constructed in many instances, the courses were weak from their want of binding to the remaining wall. As a consequence many corners have fallen, leaving the remaining walls intact. The builders often failed to tie in the partitions to the outer walls, by which failure they lost a brace and have sprung away from their attachment.
In a general way we may recognize masonry of two varieties.
1. That in which horizontal courses are obscure or absent. This has resulted from the use of stones of different sizes, the intervals between which are filled in with masses of adobe. These stones are little fashioned, or dressed only on one side, that forming the face of the wall.
2. That constructed of horizontal courses, constituting by far the larger number of these buildings. Each course of this masonry is made of well-dressed stones, carefully pecked, and of the same size. In this horizontal masonry the thickness of stones used may vary in different courses (pl. 11, b). They may be alternately narrow or thick, or layers of thick stones may be separated by one or more layers of tabular or thin stones. This method of alternation may be so regular as to please the eye and thus become decorative, a mode of decoration that reached a high development in the Chaco Ruins. The stones in the horizontal style of masonry are equal in size throughout the whole building in some cases, and show not only care in choice of stones but also in dressing them to the same regulation size. In these cases the joints fit so accurately that chinking has not been found necessary and a minimum use of adobe was required.
The inner walls of kivas are much better constructed than the outer walls of the same or of the walls about them. The masonry here is regular horizontal. The sides, lintels, and thresholds of doorways are among the finest examples of construction. With the exception of walls sheltered by overhanging cliffs, the plastering has completely disappeared, but there is no reason to doubt that the interiors of all the great houses and towers were formerly plastered.
It is instructive to compare the masonry of the great houses and towers of the Mancos with that of the towers in Hill Canyon (pl. 11, c) in Utah, the most northern extension of these two types. In Eight Mile Ruin, one of the largest of these buildings in Hill Canyon, we have a circular tower with annexed great houses, all constructed of well-dressed stones, the masonry in the walls showing on one side of the tower. No excavations, however, have yet been undertaken in Hill Canyon Ruins, and it is not known whether the unit type of kiva is found there, but the combination of great houses and towers is evident from the ground plans elsewhere published.[41]
The feature of the towers in Hill Canyon is the clustering into groups, somewhat recalling the condition in Cannonball Ruin, where, however, they are united. In the Eight Mile Ruin one of the towers is separated from the remaining houses.
Several towers have accompanying circular depressions with surrounding mounds. This association can well be seen in Holmes Tower on the Mancos Canyon and in Davis Tower and one or two others on the Yellow Jacket. These depressions, sometimes called reservoirs, have never been excavated, but from what is known of rooms accompanying towers in the western section of Hovenweep Castle it may be that they indicate kivas. Some towers have no sunken area in the immediate vicinity, especially those mounted on rocky points or perched on bowlders. At Cannonball Ruin there are several kivas side by side in one section and towering above them is a massive walled tower and other rooms.
None of the towers examined have evidences of mural pilasters to support a roof or recesses in the walls as in vaulted-roofed kivas. They are sometimes two stories high, the rafters and flooring resting on ledges of the inner wall. Lateral entrances are common and windows are absent.[42]
While the author has found no ruin of the same ground plan as Sun Temple on the Mesa Verde, D-shaped towers or great houses from several localities distantly recall this mysterious building, and there may be an identity in use between Sun Temple and the massive walled structures of the McElmo and Yellow Jacket; what that use was has not thus far been determined.[43] If they were constructed for observatories we can not account for the square tower in the South Fork of Square Tower Canyon, from which one can not even look down the canyon, much less in other directions, hemmed in as it is by cliffs. Isolated towers are often too small for defense; and they show no signs of habitation.
Are they granaries for storage of corn or places for rites and ceremonies? Do they combine several functions—observation, defense, and storage of food? Thus far in studies of more than 30 towers and great houses not one has been found so well preserved that enough remains to determine its use, and yet their walls are among the best in all southwestern ruins. Some future archeologist may find objects in towers that will demonstrate their function, but from our present knowledge no theory of their use yet suggested is satisfactory.
It is impossible from the data available to determine the century in which the towers and great houses of the region were constructed. Thus far a few were seen with great trees growing in them, but none with roofs; the state of preservation of the walls does not point to a great age. Several writers have regarded them as occupied subsequently to the Spanish conquest, while others have ascribed to them a very remote antiquity. It can hardly be questioned that the cliff-dwellers, and by inference their kindred, the tower builders, were superior in their arts to modern Pueblos.
It is important to determine first of all the forms of these towers; whether their ground plans are circular, oval, square, rectangular, or semicircular. The northern wall of many is uniformly curved and the last to fall, which might lead to the belief that the southern side, generally straight, was poorly made, but one can not determine that by direct observation, since the latter has fallen. As a matter of fact the south wall was generally low and straight, over 50 per cent of the “round” towers being semicircular, D-shaped, or some modification of that form; but we also have square and rectangular towers. It is also important to determine whether these had single or multiple chambers and the arrangement of the rooms in relation to them. This is especially desirable in towers with concentric compartments.
It is also instructive to know more of the association of towers with pueblos and cliff-dwellings or to analyze component architectural features. The tower type often occurs without appended rooms. At Cliff Palace and Square Tower House it is united with a pueblo village under cliffs; in Mud Spring Ruin it has a like relation to rooms of a pueblo in the open. Has its function changed by that union? What use did the tower serve when isolated and had it the same use when united with other kinds of rooms in cliff-dwellings and pueblos?
No writer on the prehistoric towers of Colorado and Utah has emphasized the fact that a large number of these buildings are semicircular or D-shaped, but it has been taken for granted that the fallen wall on the south side was curved, rendering the tower circular or oval.[44] In most cases this wall was the straight side of a D-shaped tower. Doctor Prudden, who first recognized the importance of a union of towers with other types of architecture in the McElmo district, says:[45] “Towers of various forms and heights occasionally form a part of composite ruins of various types.” He says also: “Several of the houses are modified by the introduction of a round tower.” And again: “At the head of a short canyon north of the Alkali, which I have called Jackson Canyon ... each building consists of an irregular mass of rooms about 200 feet long, with low towers among them.”
As our studies are morphological, dealing with forms rather than sites of towers, little attention need be paid to their situation on bowlders, in cliffs, or at the bottoms of canyons. The majority of the castellated ruins considered in the following pages are in the proposed Hovenweep National Monument, but there are others in the main Yellow Jacket and its other tributaries.
The name Hovenweep (“Deserted Valley”) is an old one in the nomenclature of the canyons of southwestern Colorado and formerly (1877) was applied to the canyon now called the Yellow Jacket, but at present is limited to one of the tributaries. The name is here used to designate an area situated just over the Colorado State line, in Utah, part of which it is hoped will later be reserved from the public domain and made a monument to be called Hovenweep National Monument.
The ruined castles and towers in this district are marvelously well preserved, considering their age and imperfect masonry. We can determine their original appearance with no difficulty and use them in reconstructing the possible forms of more dilapidated ruins, now piles of débris. The best castles and towers known to the author are localized in three canyons: (1) Square Tower Canyon, (2) Holly Canyon, (3) Hackberry Canyon. There are, of course, other castles and towers in the Yellow Jacket-McElmo region, but there is no locality where so many different forms appear in equal numbers in a small area.
The Old Bluff Road from Dolores diverges southward from that to Monticello at Sandstone post office and passes a pile of rocks visible from the road on the Ruin Canyon long before it reaches Square Tower Canyon (fig. 6). This large ruin is situated on the east rim and under it in the side of the cliff are fairly well-preserved cliff-houses. Other ruins with high standing walls were reported in Ruin Canyon but were not visited.
The duplication of names of canyons in this district is misleading. Names like Ruin Canyon are naturally applied to canyons in which there are ruins. When the author learned at Dolores of Ruin Canyon, he supposed it was a tributary of the Yellow Jacket or McElmo, but while the canyon known to cowboys at Dolores by this name has large ruins on its rim, it is not the “Ruin Canyon” to which attention is now directed. The duplication of names has led me to retain the name Ruin Canyon for one and to suggest the name Square Tower Canyon for the other.
Fig. 6.—Square Tower Canyon.
After leaving Ruin Canyon the Old Bluff Road takes a southerly course, passing through the cedars until a sagebrush clearing replaces the “timber,” where it crosses two well-preserved Indian reservoirs, or bare surfaces of rock, dipping south, the southern border having as a retaining wall a low ridge of earth to hold back the water. The retaining wall of the second reservoir has been built up by stockmen and, when the author was there, contained considerable water. Crossing the second reservoir a trail turns east or to the left and follows the road to Keeley Camp, near which are the “Keeley Towers.”
At present an automobile can approach within a mile of these ruins.
To reach the Square Tower Canyon (pls. 11-17) one returns to the reservoir on the Bluff Road and continues east about 3 miles farther, where a signboard on the left hand indicates the turn off to Square Tower Canyon. Following the new direction about southeast the great buildings are visible a mile away. An automobile can go to the very head of this canyon and a camp can be made within a few feet of Hovenweep House. If the visitor approaches Square Tower Canyon from the McElmo, he passes through Wickyup Canyon, where there are two towers on the summits of elevated buttes, not far from the junction of the canyon and the Yellow Jacket.
The castles and towers in Square Tower Canyon have been known for many years and have been repeatedly photographed.[46]
Several descriptions of these ruins have been printed, but no satisfactory studies of their structure have been published. They are recognized as prehistoric and are generally thought to have been inhabited contemporaneously with the cliff-dwellers of the Mesa Verde, being built in the same style of architecture.
The ruins in Square Tower Canyon are classified for convenience in description as follows:
(1) Ruins which have indications of inclosed circular kivas, with mural pilasters and banquettes, and closely approximated surrounding rooms. To this class belong ruins 1, 2, and 10. Of these, Unit type Ruin (No. 10) has only one kiva and belongs to the simplest or unit form of the pure type. Ruins 1 and 2 have two or more kivas and are formed by a union of several units, combined with towers and great houses. (2) Ruins, the main feature of which is absence of a circular kiva. The Twin Towers belong to this second or “great house” type. The few cliff-dwellings in this canyon are small, generally without kivas, resembling storage cists rather than domiciles.
This ruin (fig. 7), the largest in the canyon, is situated at the head of the South Fork. Although many of its walls have fallen, there still remains a semicircular great house (B, C, D) with high walls conspicuous for some distance. The ruin is a pueblo of rectangular form belonging to the pure type, showing circular depressions identified as kivas (K), embedded in collections of square and rectangular rooms, and massive walled buildings (E) on the south side.
Fig. 7.—Ground plan of Hovenweep House.
The standing walls of the ruin are remains of a conspicuous D-shaped tower (B, C, D), which is multichambered. Its straight wall measures 23 feet, the curved wall 56 feet, and its highest wall, which is on the northeast corner, is 15 feet high. At the northwest angle of the ruin (A) there stand remains of high walls which indicate that corner of a rectangular pueblo. Hovenweep House (pl. 14, a) was the largest building in this canyon, but with the exception of the addition of a semicircular tower or great house, does not differ greatly from a pueblo like Far View House on the Mesa Verde. The piles of stone and earth indicating rooms below justify the conjecture that when the fallen débris is removed the unfallen walls will still rise several feet above their rocky foundations. If properly excavated, Hovenweep House would be an instructive building, but in its present condition, while very picturesque, its structure is difficult to determine.
Fig. 8.—Ground plan of Hovenweep Castle.
This ruin (pls. 14, b, c; 18, b), like the preceding, has circular kivas compactly embedded in rectangular rooms arranged about them, indicating the pure type of pueblos. The massive walled semicircular towers and great houses are combined with square rooms and kivas, indicating that it is distinguished by two sections, an eastern and a western, which, united, impart to the whole the shape of a letter L (fig. 8).
The western section (fig. 8, A-D, M) of Hovenweep Castle is made up of five rooms, the most western of which, M, is semicircular, while A, B, C, and D are rectangular. Room A is almost square, one of its walls forming the straight wall of the south side of the semicircular tower, M. At the union its walls are not tied into the masonry of the circular wall of the tower, as may be seen in the illustration, plate 14, b, implying that it was constructed later. There is an entrance into A from the south or cliff side, and a passageway from A to Room B, which latter opens by a doorway into Room C. All rectangular rooms of the western section communicate with each other, but none except A seem to have had an external entrance. The photograph of the south wall of the west section of the ruin (pl. 14, c) shows small portholes in the second story and narrow slits in the tower walls. The lower courses of masonry are formed of thinner stones than the rows above, but smaller stones compose the courses at the top of the wall. A view of the north wall of the western section (pl. 22, a) shows the tower and rooms united to it. There is no kiva in the western section.
The longest dimension of the western section (pls. 12, 14, c) is approximately east-west; that of the eastern is nearly north-south. The eastern section (fig. 8, E-L), like the western, has a tower (L), which is situated between two circular depressions or kivas (K). On the north and south ends the eastern section is flanked by rectangular rooms. Those at the north end were better constructed, and even now stand as high as the walls of the western tower. The views show that their corners are not as well preserved as their faces, which is due to defects in masonry, as lack of bonding. Although much débris has accumulated around the kivas, especially in their cavities, it is evident that these ceremonial rooms were formerly one storied, and practically subterranean on account of the surrounding rooms. Several fragments of walls projecting above the accumulated débris indicate rooms at the junction of the eastern and western sections of the ruin, but their form and arrangement at that point are not evident and can be determined only by excavation. The inner kiva walls show evidences of mural pilasters and banquettes like those of cliff-dwellings and other pure pueblo types.
The square tower (pl. 11, a), standing on a large angular rock in the canyon below Hovenweep Castle, is a remarkable example of prehistoric masonry so situated that it is shut in by cliffs, rendering the outlook limited. Several published photographs of this tower give the impression that it stands in the open and was an outlook, but that this is hardly the case will be seen from a general view looking west up the South Fork.
This ruin is a small tower situated in a commanding position on the point of the mesa where the canyon forks. The section of the wall still standing indicates a circular form, the north side of which has fallen; the part still intact, or that on the south side, exhibits good masonry about 8 feet high (pl. 15, c).
The walls of the north segment of a tower stand on a large angular block of stone rising from a ledge above the arroyo, or bed of the canyon, below Ruin 4, on the South Fork. What appears to have been a doorway opens on its north side; this opening is defended by a wall, remains of a former protected passageway into the tower.
On the perpendicular cliff of the precipice near Ruin 5 and below the point on which Ruin 4 stands there are several almost illegible pictographs, below which are rather obscure evidences of a building, the features of which can be determined only by excavation.
Instructive features of Tower No. 5 are two parallel walls, one on each side of the doorway, like those of the circular towers on the promontory at the junction of the Yellow Jacket and McElmo. Other towers on the canyon rim show defensive walls, as in Ruin 9, constructed about their entrances from corners of the buildings to the mesa rim, effectually preventing passage. Morley and Kidder have suggested that the walled recess in the cliff below Ruin 9 was probably built to prevent access from below. This feature is found in the floor entrances of a building near the Great House of the Holly group.
This ruin is a small tower whose curved walls are so broken down that the form is not evident. It is situated in the base of the talus at the head of the South Fork (pl. 26, a).
This house, more remarkable from its site than its structure, was constructed in an eroded cave of a bowlder halfway down the talus of the cliff. The front walls are somewhat broken down, but others built in the rear of the cave still remain intact. On the top of the bowlder is the débris of fallen walls, suggesting a former tower, but not much remains in place to determine its outlines. Where the walls are protected the mortar shows impressions of human hands and at one place there are the indentations of a corncob used by the plasterers to press the mortar between the layers of stone. There were formerly at least two rooms in the rear of the cave, the front walls of which have fallen and are strewn down the talus to the bottom of the canyon.
The so-called Twin Towers, which seen together from certain points appear as one ruin (pl. 15, a, b), rank among the most impressive buildings in Square Tower Canyon. They stand on the south side of the canyon on a rock isolated by a cleft from the adjoining cliff. The larger (fig. 9, A-E) has an oval ground plan and a doorway in the southwest corner; the smaller (F, G, H, I) is horseshoe shaped with a doorway in the east wall, which is straight. The arrangement of rooms is seen in figure 9. Small walled-up caves are found below the foundation on the northwest base of the larger room.