15] STUDY OF SOUTHERN WISCONSIN FISHES— CAEN 15 



part of its course parallels the base of the moraine, but tends to leave it 

 near the western limit of the county. For the most part it has cut a bed 

 through rich black soil, flowing in a channel from ten to thirty feet wide. 

 Its bed is characterized by many deep pockets located with definite rela- 

 tion to the innumerable bends in the course of the river, these holes afford- 

 ing ideal places for game fish. Areas of swift water occur, in which a fine 

 gravel bottom affords habitat for swift water forms and offers breeding 

 grounds in abundance for the many species of minnows choosing such 

 localities. As a fishway it is far more important than the Oconomowoc 

 river because of the lack of dams. A dam at Rome a short distance west 

 of the county line has flooded a large area which abounds in game fish, 

 and there is no serious barrier to river migration in both directions nearly 

 across the entire county (to Merton). This is especially important because 

 of the number of lakes involved in the course of the river. One important 

 tributary the Bark river has in Scuppernong creek, which edges in between 

 Bark river and the moraine as the former leaves the higher ground. This 

 stream drains a large area of swamp land, and exchanges with the Bark 

 river an abundant fish population. Still farther to the south the Scupper- 

 nong river intrudes between the Bark river and the moraine. This river 

 rises in Little Silver lake, a small, spring-fed body of water, and flows 

 through a vast swamp area in the southwest corner of the county, to unite 

 with Bark river south of the town of Hebron in Jefferson county. Within 

 the county limits it is a small river of very soft bottom and water stained 

 a deep brown from the decomposition of organic matter. 



The Fox river rises from a series of springs in the northeastern corner 

 of the county, a short distance north of Lannon. From here it flows in a 

 general southwesterly direction, its valley lying between two morainic 

 ridges. Its course takes it through regions of rock and swamp, agricultural 

 land of high quality and regions of gravel, so that the bed of the river 

 offers an alternation of conditions which meet the requirements of a wide 

 range of species of fishes. Near its source it is a tiny stream with patches of 

 Potamogeton furnishing shelter for many head-water species of minnows 

 as well as to the grass pickerel (Esox vermiculatus) , this representing one 

 of the most northern records of the species. Within eight miles of its origin 

 the river widens rapidly and becomes a stream over a hundred feet wide 

 as it flows through the city of Waukesha. From here it traverses vast 

 swamp areas where it receives many small tributary creeks. It abounds in 

 carp (Cyprinus carpio) whose great numbers and constant activity keep 

 the water in a constantly muddy condition. At this point its general course 

 is almost due south, and it leaves the county as a river more than two 

 hundred feet wide with low, boggy, undercut banks and water of a deep 

 brown, opaque appearance. Throughout its entire course within the 

 county its flow is unobstructed, affording excellent opportunities for fish 



