OBSTRUCTIONS TO THE ASCENT OF FISH IN RIVERS. 633 



heads in the Jordan Eiver, "which is a very cold, rapid stream, cou- 

 taiuing the Thymallus tricolor, of Cope. The mouth of the Pine is a 

 sharp rapids. 



Elk Eapids, though emptying a large quantity of water into Grand 

 Traverse Bay, would probably not be favorable for salmon, as it heads 

 in a series of large lakes. 



The Carp Eiver. 



The Betsey Eiver. 



The Manistee is a large, long river, emptying through a lake and 

 a bay. The headwaters are very cold, and contain the grayling. There 

 are twenty-eight mills, all steam, built on the shore of the lake, and an 

 immense number of logs are rafted down every year. I believe the 

 sawdust at the mouth would not be as objectionable for salmon as for 

 whitefish, as I suppose they frequent the milling-rivers in Maine and 

 along the Canada shores. 



The Muskegou is another large stream containing the grayling, which 

 is, I suppose, an indication of its being clear and cold. 



There are other streams farther south ; but the northern streams are 

 probably most favorable for salmon. 



The Escanaba Eiver should be considered very favorable. 



The Monistique is a favorable river if the steam saw-mill is left out 

 of consideration. 



The Pine Eiver is especially favorable ; it has a very sharp rapid at 

 its mouth. The Jordan, at the head of the south arm of Pine Lake, 

 would be a most favorable spawning-ground, as no dams obstruct the 

 passage of the fish to its headwaters. 



The Manistee has, perhaps, too many mills, and has also a large expan- 

 sion into a lake not more than two miles long. Its broad waters 

 would, undoubtedly, be favorable spawning-ground. 



