parts of the lakes vegetation is very abundant. Large beds of 

 rushes (Scirpus validus Vahl.) appear in Marble, and especially 

 in Robinson (or Kettleson) lakes, chiefly on the southern and 

 western sides, nearer the flat, treeless shores. Here, as else- 

 where, these rush-beds seem to mark the location of low bowldery 

 or gravelly ridges or areas. Most of the beaches of these lakes 

 are soft and very muddy, but the eastern shore of Marble lake is 

 largely sandy. A ridge nearly 50 feet in height separates 

 Marble and Robinson lakes, and extends between Marble and 

 Hottes lakes, where it drops to about 35 feet. This ridge is flat, 

 with abrupt slopes or banks, and is interrupted by sags which 

 connect the three lakes during high water. A low place on the 

 northeastern side of Marble lake provides an outlet into Spirit 

 lake during high water. The level of the water in these smaller 

 lakes is approximately that of the water in Spirit lake. That 

 part of Little Spirit lake, another member of this group, which 

 lies in Iowa, is also shallow, and usually overgrown with aquatic 

 vegetation. It connects with Spirit lake across^ the narrow 

 ''causeway" near the center of section 8. A prominent wooded 

 ridge extends between its two lobes but the southern and western 

 shores of the west lobe are low and treeless. The great swamp 

 or bay which extends northward into Minnesota from Crandall 's 

 Lodge is also rich in vegetation. 



Several smaller bodies of water are found in the Hottes lake 

 region, the most interesting being Sunken lake which lies be- 

 tween Hottes and Marble lakes. This is a small lake which has 

 been comparatively recently formed, according to tradition. It 

 is completely enclosed by high, abrupt banks excepting for a 

 narrow connection with Hottes lake, and is surrounded by for- 

 est. The rougher part of this section is heavily wooded and the 

 region presents a variety of forest, prairie, swamp and lake con- 

 ditions of great interest to the botanist and zoologist. 



Excepting in the Hottes lake region there is but little timber 

 bordering Spirit lake. It is a striking fact that the forest fringe 

 is found only where there are abrupt, high banks. In such places 

 the banks are usually bowldery. The flat shores, usually sandy 

 or muddy, which gradually rise to the prairies beyond are tree- 

 less. The shaded areas on the map represent the forest, and 

 also, therefore, mark the location of the higher banks and rougher 

 surfaces. 



6 



