368 ARTHUR C. TROWBRIDGE 



The lake surface apparently stood at this level (970 feet) for a 

 time, perhaps because the outlet had made a resistant bed for itself 

 by the accumulation of bowlders on its bottom. The evidence of 

 this stage is a well-defined beach or barrier ridge of sand across the 

 north end of the lake, whose crest is 8-10 feet above the lake and 

 which confines a low, peaty area between it and the moraine. This 

 low area back of the ridge was clearly once a lagoon. The ridge 

 has been so strengthened artificially that it is impossible to tell 

 whether or not it was originally broken at the old outlet, but water 

 which could reach the top of the ridge could today flow north 

 through the old outlet to the Baraboo River. 



During this second stage of the lake it is believed still to have 

 been receiving water from the Peck and Steinke basins (though the 

 lakes of these names were extinct) and from a later post-Glacial 

 lake northeast of the Steinke flat, which has become known locally 

 as Shubring Lake. Shubring Lake occupied what is now a flat 

 area, 1 mile by f mile in extent, 4 miles northeast of Devils Lake, 

 and just across the terminal moraine from the Steinke flat in the 

 area of ground moraine. The Shubring flat is bordered on the 

 north, west, and south by the inner edge of the terminal moraine 

 and on the east by a drift-covered hill of quartzite. The slopes 

 toward the flat are almost covered in a narrow belt parallel with the 

 edges of the flat by thousands of bowlders which almost form a 

 wall around the old lake bottom and which were concentrated on the 

 shores of the shallow lake by "ice push." This lake was formed as 

 the edge of the ice retreated, leaving an inclosed basin. During the 

 first stages of recession of the ice, the lake received glacial waters, 

 and after the ice had left the confines of the basin precipitation 

 formed the source of supply. The line of outlet of the lake is plainly 

 seen as a flat-bottomed, bowlder-strewn, linear depression interrupt- 

 ing the course of the terminal moraine from the southwest end of 

 the Shubring flat to the Steinke flat south of it, and now used by 

 Mr. Shubring as a roadway across the terminal moraine. The 

 bottom of the valley which was the site of the outlet and the 

 bowlder wall around the lake flat are at the same altitude (hand- 

 level measurement), and not more than 2 feet above the level of 

 the flat. The original depth of the lake is unknown, no records 

 of the depth of the lacustrine fill being available. 



