292 GEOLOGICAL SURVEY OF THE TERRITOEIES. 



scarcely to be exjiectcd. The northeastern part of the State may be 

 cliaracterized as tlie region of swamps and bo^s. A strip of some fif- 

 teen or twenty miles in width aronnd the western end of the lake — which 

 is required to reach the summit of the bkiff — and which is rapidly as- 

 cending and mostly rugged, as a matter of course is well drained; 

 but as soon as we pass beyond this limit we enter upon a succes ion of 

 bogs and swanii)s separated by low ridges a few feet in height, which 

 contiiiue until we come near to the ]Mississippi, and are, infact, re])eated 

 for a short distance west of it at some ])oints. These ridges, which 

 appear to be composed entirely of drift-material similar in character and 

 color to the underlying or neighboring rocks, seem to have a general 

 iiortli and south or northeast and soutlnvest direction. Tliis parallel- 

 ism of even these small swells between the boggy flats is but a repeti- 

 tion on a small scale of a remarkabU; feature of this part of the North- 

 west to which I have already alluded in speaking of the course of the 

 rivers. Owen calls special attention to it in his report ou the geology 

 of this region as follows, (chapter iv, p. 333 :) 



As v,^l)at I conceive to have been grenfc vnlleyK in the rocky strata of large portions 

 of Wisconsin and Miun(>sota have been lilied np, and the conntry, in a great nieasnre, 

 hiveled by the accnmuhition of immense deposits of driit, it is not possible to determine, 

 -with anytliiug like acennicy, the width of the original valleys, nor the exact lines of 

 the anticlinal axis separating them ; but the distances from one synclinal line to 

 another may be ascertained now, witli as much precision as the linear surveys of that 

 region, together with the draughts of the principal streams in the unaurvcyed portions 

 of the Territory, l)y menibei's of the geological corps, will permit. Thus, from the 

 valley of Chippewa River, at the month of Manidowisli to that of the Upper Saint 

 Croix, in a direct line an<l at right angles to the course of the valleys, is about sixty 

 miles ; and from the valley of the Saint Croix to that in which the Mississipj)i flows, 

 between the outlet of Sandy Lake and the month of Crow' Wing River, in the same 

 direction across the strike of the valleys, is about sixty-two miles ; and from this por- 

 tion of the valley of the Mississippi to the next parallel valley — in which Leech La^ke 

 is situated — is aboiit fifty miles ; and from the valley of Leech Lake to the next great 

 parallel valley northwest of it — the one in which Red Lake lies — is about sixty-eight 

 miles ; showing a remarkable degree of uniformity in the undulations of the crust of 

 the earth throughout a very extensive region of conntry. * * There are 



three great systems of valleys in the Northwest, besides numerous subordinate ones, 

 the valleys of each system preserving a very uniform degree of parallelism with one 

 another and with the smaller valleys between the anticlinal axes. 



He then proceeds to enumerate the various valleys of these systems 

 by the names of the rivers occupying them, showing this parallelism to 

 prevail to such an extent, not only in regard to the larger valleys and 

 streams, but even in respect to the numerous smaller water-courses and 

 valleys, as to make it evident that it arises from some law connected 

 with the geological forces and structure. lie gives it as his opinion 

 that the great structural features of the country are due to subterranean 

 movements, acting at different periods on an immense extent of the 

 crust of the earth and with great uniformity during each epoch, and not 

 to local disturbances only or to mere alterations of the surface from 

 glacial or diluvial action, however much these agencies may have 

 altered the face of the country. 



This may be, and doubtless is, true in regard to the direction of the 

 larger divides and valleys, but it will scarcely apply to the small ridges 

 which separate the bogs and swamps of Northeastern Minnesota or the 

 smaller parallel ridges of Dakota and Nebraska. Water alone, or water 

 and wind were certainly the forces that formed these ; perhaps glacial 

 action may have played a part in originally outlining them. 



Leaving the nortlieasteru part of the State and moving westward 

 across the Mississij)pi toward th'C opposite boundary of the basin, we 

 observe a very marked and important change in regard to the surface- 



