IOWA ACADEMY OF SCIENCES. 65 



The mountains in the immediate vicinity are composed of intrusive pranite^ 

 which also underlies the detritus below the mouth of the canon and crops out here 

 and there in low knolls and ridf^es. In two such pranite knobs, about one hundred 

 yards apart and one-fourth of a mile from the mouth of the canon, the excavations 

 are found. One of these, which is quite bare, contains a small number. The 

 other is partly over-laid and partly fringed with larpe granite rocks, all more or 

 less tilted or moved from place. On this knoll, some in detached rocks, some in 

 undisturbed granite, are upwards of sixty excavations. All stand nearly or quite 

 perpendicular, the detached rocks having undergone little change of position since 

 the excavations were made. 



A description of this group will sei-ve the purpose of this paper. 



The excavations themselves are of two kinds, which differ both in size and 

 shape. The larger, thirty-two in number, are uniformily semi-fusiform, the 

 diameter and depth being about in the proportion of three to five. The largest of 

 these measures fourteen inches in diameter at the mouth, and nineteen inches in 

 depth. A small one is ten and one-half by fourteen inches; a wide one, fifteen by 

 sixteen inches; a narrow one, twelve by eighteen inches. 



The wide excavations are, naturally most weather-worn, other things being 

 equal. A few in sound granite and particulary narrow or shaded holes, are in a 

 perfect state of preservation. Fourteen are well preserved. Five, made near an 

 edge of a rock, have been partly worn away on the outer side; one sirailai-ly situ- 

 ated has been split open lengthwise and others, crowded in a small! area, are more 

 or less fractured. 



Twelve excavations, in seperate groups of five and seven, are found a few steps 

 apart from the rest and are more exposed. The remainder lie in or near the 

 shadow of a large, tilted block of granite. These excavations also appear oldest, 

 and in the shade are much crowded. 



Scattered among or near these shaded excavations are found more than thirty 

 smaller basin-shaped ones, which, moreover, occur nowhere else. These vary in 

 size from six inches wide by three inches deep, to two inches wide by ©ne-half inch 

 deep. Seven only are of the former size, the majority being much smaller. 



Some plainsmen say that the excavations are Indian grain-mortars; others as- 

 sert that they are cooking-holes in which food was boiled by throwing heated 

 stones into the water covering it. It has been suggested, also, that they were 

 used for crushing ores, but the absence of any workable ore in the vicinity would 

 seem to render this improbable. The writer would add that they may have served, 

 also, for the storage of water from the spring which is somewhat difficult of access. 

 They were, however, doubtless used for a variety of purposes as occasion required. 

 The basin-like excavations probably served to hold round-bottomed vessels, such 

 as are still used by the Indians of the Southwest, or the largest of them may be 

 mortars . 



The knoll was, presumably, a camping place for hunting parties or roving 

 bands. The site commanded an extensive view of the mesa and of the approaches 

 to the spring, and the loose rocks afforded shade and an ambush to the hunter and 

 concealment from enemies. 



No excavations are known to exist in the canon near the spring, though 

 suitable rocks are abundant. Such a site would be distant from the trail and 

 further from the mesa. Preference for this rock-covered knoll was quite natural. 



Numerous small fragments of pottery were found, both plain and decorated, 

 and resembling very much in quality and style of adornment some of the modem 



