THE HISTORY OF DEVILS LAKE, WISCONSIN 355 



were made by the Wisconsin and Baraboo rivers developing their 

 courses on the surface of the Paleozoic rocks, cutting down through 

 these rocks and becoming superimposed on the ranges, and holding 

 their courses. In the case of Devils Lake gap, at least, this 

 hypothesis seems to involve too nice a coincidence. Whether the 

 pre-Cambrian gap was continuous or made up of two valleys with a 

 col between, Martin's idea would mean that a crooked stream 

 starting on a surface 1,200 feet or more above final grade, cuts down 

 more than 300 feet, then develops a flat surface and deposits fine 

 gravel without ceasing to cut, is superimposed on quartzite in a 

 course exactly coinciding with a peculiar pre-existing filled and 

 buried crooked valley, and then cuts on downward for 900 feet 

 without interruption. 



It seems more likely to the writer that the explanation of the 

 reoccupation of the gap by a stream is to be found in the applica- 

 tion of the principle of stream adjustment on non-resistant rocks 

 during a cycle of erosion which went nearly to completion. On the 

 1,400-1,480 foot surface, the streams flowed here on quartzite and 

 there on sandstone. With the uplift of the surface, these streams 

 began to intrench themselves and new tributaries were formed. 

 The larger streams reached grade after cutting 200 feet or so. 

 For most of the streams this downward cutting was through 

 quartzite. The stream which adjusted on the non-resistant 

 sandstone in the gap cut more rapidly than the others, obtaining 

 an advantage in this way; it became a pirate and gradually cap- 

 tured many of the other streams. That there were other streams 

 during this cycle and that they did intrench themselves before 

 being captured is proved by the fact that there are passes or cols 

 across the range at altitudes a little above 1,200 feet, as, for instance, 

 where the West Sauk road crosses the range between the heads of 

 Skillett's Creek and Otter Creek. 



At any rate, it was during this cycle of erosion that the Wis- 

 consin or its pre-Glacial ancestor came to flow southward and west- 

 ward over the present site of the Lower Narrows, up the present 

 course of the Baraboo valley and southward through the shallow 

 Devils Lake gap, and the Baraboo River entered the inclosure 

 between the quartzite ridges through the Upper Narrows, and 



