NATURAL AREAS AND REGIONS 



473 



Skokie marsh so that this entire bit of 

 moorland amounting to over 2000 acres 

 will in time be preserved from drainage 

 projects and kept in its primitive 

 condition. 



Cook County's forest preserves are 

 distributed as follows: 



Districts: Acres 



Palos 6,688.48 



Desplaines 5,274.26 



North Branch of Chi- 

 cago River 2,696.27 



Chicago Heights, Bloom 



and Thornton 2,248.76 



Calumet State Line .... 2 , 135 . 82 

 Salt Creek and River- 

 side 1,236.66 



Palatine 1,102.08 



Elk Grove 1,273.48 



Orland 734.35 



Skokie 503.90 



Lyons 367.94 



Oak Forest 227.20 



Beverly Hills 160.13 



Schaumburg 50. 65 



Evanston.. 6.68 



Total 24,806.62 



a. Upland areas 



*County Line Preserve. (Cook County 

 Preserves.) A small tract of swampy 

 woods at the margin of the Skokie 

 marsh. Near Braeside Northwestern 

 R. R. 20 mi. north of Chicago. W. C. 

 Allee. 



p. North Shore Ravines. (C4.) The 

 ravines between Winnetka and Wauke- 

 gan in Cook and Lake Counties. These 

 ravines contain a rich mesophytic flora 

 in an essentially natural state. These 

 are notable for being almost the only 

 stations for beech (Fagus grandifolia) 

 in northern Illinois. They also contain 

 various plants of northern range. In 

 most of these ravines the public is not 

 particularly welcome. The animals here 

 are those typical of mesophytic woods. 

 The ravine streams are mostly con- 

 taminated, so much so that in many 

 cases the resistant water isopod, Asellus 

 communis, is lacking. In others the 

 sensitive May-fly nymphs may be found. 

 The ravines may easily be reached via 

 the N. W. R. R. or Milwaukee Electric 

 which runs near Lake Michigan. Per- 



sons visiting these ravines may see 

 several in a day. An excellent example 

 is within the military tract at Fort 

 Sheridan. H. C. Cowles. 



*Deer Grove. (B3C3.) (Palatine Pre- 

 serve, Cook County.) Artifically en- 

 larged, natural lake with practically 

 entire drainage basins of two tributary 

 brooks. About 1200 acres. Open red 

 oak forest with elms along water courses. 

 Some hickory and maple present. Tim- 

 ber is oak-hickory type. Streams small, 

 but permanent. Many temporary and 

 a few permanent ponds. Partly rented 

 for grazing. Prairie Club permanent 

 camp. 



Chicago 28 mi. S.E., Chicago and 

 Northwestern 2.5 mi. N. (w or a) Pala- 

 tine, 111. W. C. Allee. 



* Elk Grove Preserve. (B3-C3.) (Cook 

 County.) Two or more mi. south of 

 Arlington Heights on Chicago and 

 Northwestern R. R. Swampy land; 

 contains both banks of Salt Creek for 

 about two mi. The creek is relatively 

 free from contamination at this place. 

 W. C. Allee. 



b. Desplaines River Preserves 



Scattered tracts along the Desplaines 

 River taking in much of the river bank 

 from Riverside to the County Line. 

 The river is badly contaminated for 

 most of the distance, but approaches 

 natural conditions near Wheeling where 

 it has been dammed. Large numbers 

 of river mussels occur below Wheeling. 

 Riverside shows some of the best 

 forest. 



*Riverside Flood Plain and Savanna 

 Forest. About 20 acres along the Des- 

 plaines River; typical mature flood 

 plain forest of maple, elm, bass wood, 

 walnut and oak. Shows succession 

 from middle age to mature stage. For- 

 est edge with sinuate outlines, outlying 

 groves; grass covered portions, typical 

 mesophytic prairie ; general aspect char- 

 acteristic of large areas in Illinois oak 

 grove savanna. The fauna of the 

 forest edge is especially characteristic; 

 in the forest, raccoons, gray squirrels, 



