■"4.5 



z 



UJ4.0 

 O 



X3.5 

 O 



3.0 

 a 



in 



o 1.5 



■STARVED ROCK 



1 t:0CK a DA M :■!! ■•■ 



STARVED ROCK POOL 

 30 JULY 1965 

 0725 to 10*3 CST 

 TEMP 26 4 to 290"C. 



.-V ,— ' 



UiR5£ILLES POOL 

 ^9 JULf ,965 

 0650 10 1122 CST 

 TEMP 29 5° to 302° C, 



196! 



DRESDEN POOL 



0835 10 1035 CST 

 TEMP 302* 10 32i"C. 



V\ 



\.' 



230 234 238 242 246 250 254 258 262 266 270 274 278 282 286 290 

 MILES FROM MISSISSIPPI RIVER 



RIP UF Annw 

 LOWER END PEORIA DETWEILLER PEORIA LAKE Ilqugh 



PEORIA LAKE^^ / NARROWS P*"" LIGHT \^CHILLICOTHE__,/ LACON 



LAKE SENACHW1NE 

 HENRY ^ HENNEPIN 



VERMILION 

 PERU RIVER 



SPRING VALLEY ' LASALLE 



33.0r 



PEORIA POOL . 



6 8 7 AUGUST 1964 I 5 AUGUST 1965 ' 



0528 10 1113 CST 0808 to 0930 CST 



TEMP 27 2° 10 29 7°c1tEMP 25 6" Io 26.8°C. 



186 190 194 198 202 



MILES FROM MISSISSIPPI RIVER 



M, 15, 16 JULY 1964 I 1 1 AUGUST I9G9 

 0517 to 1020 CST 0545 to ll56 CST 



TEMP. 23.3° to 26.2° C.I TEMP. 25.0° to 25.7° C 



MILES FROM MrSSISSIPPt RIVER 



MISSISSIPPI RIVER 

 GRAFTON 



M0NTE7UMa FLORENCE 



NAPLES MEREOOSIA 



ALTON POOL 

 12 AUGUST 1965 

 0530 to 1515 CST 

 TEMP. 23.9° to 27.1° 



V,= 



32 36 40 44 48 



MILES FROM MISSISSIPPI RIVER 



Fig. 3. — Dissolved oxygen determinations in the Illinois River from Brandon Road Lock and Dam to Grafton. Broken lines 

 represent readings taken in the summer of 1965; solid lines represent readings taken in the summer of 1964. (Illinois Natural His- 

 tory Survey data.) 



10 



