EXTENT OF SAINT CROIX RIVER AND BASIN 15 



the hike Saint Croix. Several hxr*>je trihutaries flow to the Saint Croix 

 river from each side, and the maxiniuni width of the drainage hasin is 

 ahout SO miles, from the beginnin<!;s of the Kettle river in Minnesota 

 southeast to the farthest si)rings of the Yellow river in Wisconsin. 



According to Mr James L. Greenleaf, in his " Report on the water 

 power of the Mississippi river and some of its tributaries," contained in 

 volume 17 of tlie quarto final reports of the tenth United States census, 

 for 1880, published in 1887, the drainage area^ of the Saint Croix com- 

 prises 7,576 square miles, of which slightly more than half lies in Wis- 

 consin. The volume of the river at its mouth in the stage of low water 

 is stated to be 2,800 cubic feet per second, and the average flow about 

 6,200 cubic feet per second for the whole year. 



The chief tributaries from .Wisconsin-are the Namekagon river, stated 

 by Greenleaf to be 85 miles long, draining an area of 1,025 square miles ; 

 the Yellow river, 50 miles long, draining 310 square miles; the Clam 

 river, also 50 miles long, draining 416 square miles; W^ood river, 30 

 miles long, draining 168 square miles ; Apple river, 55 miles long, drain- 

 ing 427 square miles ; and Willow river, 35 miles long, draining 246 

 square miles. 



From Minnesota the Saint Croix receives the Kettle river, noted as 70 

 miles long, with the largest tributary drainage area, 1,093 square miles ; 

 the Snake river, 78 miles long, draining 937 square miles; and the Sun- 

 rise river, 30 miles long, draining 292 square miles. 



Table of Altitudes 



The following altitudes along the Saint Croix river, given in feet above 

 the sea, from leveling by United States engineers in surveys for convert- 

 ing some of the abundant lakes of its head streams into a reservoir sys- 

 tem, and from railroad surveys, show that the main stream has a descent 

 of about 400 feet : 



Feet 



Springs at liead of the South branch of the Bois Bral6 river. .... 1,068 



Springs at head of the Saint Croix river 1,070 



(These springs rise in the same marsh, 600 feet apart, the Bois Brul6 

 river running north, the Saint Croix south. An ancient watercourse 

 exists liere, mainly about a mile wide, bordered by drift bluffs 75 feet 

 high, with their crests 1,140 to 1,150 feet above the sea. It was the 

 outlet of lake Superior when the receding ice-sheet on the northeast, 

 acting as a barrier to the present course of outflow, held this lake about 

 500 feet higher than now\) 



Upper Saint Croix lake 1,011 



Saint Croix river at Gordon, Wisconsin 1,006 



Same, low water, above and below the " Big dam " 1,005 and 1,001 



