TO JUNCTION OF GRAND AND Gh'KKN ESIVBRS. 85 



Verde, facte of which the significance will be readily appreciated: but these are not 



all the things that may be seen from the vicinity of our present standpoint. The Mesa 

 Verde is, geologically, bu1 a portion of the high table-lands which border the I pper 

 San Juan; the northern margin of which is followed by our route from the lord ot the 

 Chama to the Mancos. Here tins plateau terminates abruptly in a hold and most pic- 

 turesque wall, of which the general course, though varied by many salient and 

 re-enteriner angles, is nearly north and south from the Sierra de la Plata to the San Juan, 

 This mesa we completely encircled: examined it at a thousand points, and can speak 

 of its structure and extent with confidence. To obtain a just Conception of the enor- 

 mous denudation which the Colorado Plateau lias suffered, no better point of view 

 could possibly be selected than that of the summit of the .Mesa Verde, The geologist 

 here has, as it seems to me, satisfactory proof of the proposition I have before made, 

 that, from the greater portion of the Colorado Plateau, strata more than 2,000 feet m 

 thickness have been removed by erosion. He here has a view toward the west, limited 



only by the powersof human vision. Directly west the Sage-plain stretches out nearly 

 horizontal, unmarked by any prominent feature, to the distance of a hundred miles. 

 There the island-like mountains, the Sierra Abajo and Sierra La Sal, rise from its sur- 

 face. South of these is the little doubled-peaked mountain, called by the Mexicans Las 

 OrejOS del 0S0 — the bear's ears: beyond these his vision could not reach, but our 

 explorations enable us to tell him there lies the broad eroded valley of the Colorado, 

 bounded by two steps, of over 1,000 feet each, below the level of the Sage-plain, and 

 in the bottom of that valley, the chasm of the Colorado Cafton, whose perpendicular 

 walls are 1,500 feet in height; beyond the trough of the Colorado, a plateau corre- 

 sponding to the Sage-plain, ami beyond this a representative of the Mesa, Verde. 



Looking southwest, he would see the Sage-plain terminated in that direction by the 

 excavated valley of the San Juan: beyond this its representatives of similar character 

 and elevation; higher and more distant than these, the long perspective lines.)!' the 



lofty mesas north ami wesfrof the ftfoqui villages: the precise counterpart ot that on 

 which he is supposed to stand. 



On the northern margin of the plateau, we are assured by those who have been 

 there thai the constituent rocks of the Mesa Verde are exposed, holding the same posi- 

 tions as here Are we not then driven by these fads to conclude that, overall this 

 area of undisturbed sedimentary rocks, surrounded by table-lands composed oi like 

 strata, presenting corresponding, but now widely separated faces, these strata once 

 Stretched in unbroken connection: and that, from theereat interval, where now wanting, 

 they have been removed bv die same all-potent influence which has lett such grand 

 and so similar records in the canons of the ( lolorado and its tributaries. 



The "-coIo-a of the country Lying between the Sierra La Plata and Sierra Abajo 



DO, . ..... 



is so monotonous as to require no lengthy description; all thai need be said ot it is 

 in brief notes of our diiVeivnt days' marches contained in my journal. From these 1 

 make the following extracts: 



"Attgust 1<>///, ('"ii//) 21, on llin Dolores. — 'The llio de los Mancos is a clear mount- \ 

 ain stream, formed by two branches, which unite just below our camp, and which 

 rise in the foot-hills of the Sierra de la Plata, on its western side. Each of the two 



