167 

 G 0.0 GIBRALTAR CREEK (Gibraltar lake) 



LOCATION: 59°23'12" N. 15l+°57'12" W. 



PREVIOUS NAMES OR NUMBERS: Ai+, Kakhonak Creek 



U.S.G.S. MAP: Iliamna, 1:250,000; Iliamna B-5, 1:63,360 



PHYSICAL DESCRIPTION 



TOTAL LENGTH: 5-8 miles 



LENGTH ACCESSIBLE TO SAIWON: 5.8 miles 



AVERAGE WIDTH: 95' RANGE: 60'-100' 



AVERAGE DEPTH: 24" RANGE: l8"-48" 



TOTAL ACCESSIBLE SPAWNING AREA: 322,3^ square yards {66.6 acres) 



POTENTIAL SPAWNING AREA: 60^, 193,600 square yards (lj-0.0 acres) 



BOTTOM QUALITY: 2^ <l/8", 52^ l/8"-3", 33^ 3"-12", 13^ >12". Excellent 

 gravel in lover k miles and upper O.5 mile. Much rubble and bovilder 

 above k miles to within O.5 mile of Gibraltar Lake. Bottom stable. 



WATERSHED: 128 square miles. Creek flows through a narrow cut about 50 ' 

 below surrounding terrain for its entire length. Willow, alder, and 

 birch thickets along stream. Subject to occasional flooding. Source: 

 Gibraltar lake. 



GRADIENT: 23 '/mile 



WATER VELOCITY: 2.0 fps 



FLOW: 235 cfs (Sept. 8, I961). Measured RANGE: 

 0.2 mile below Gibraltar Lake, normal 

 sxamner flow. 



AIR TEMPERATURE: k.0° C. (Sept. 8, I961) 



WATER TEMPERATURE: 10.0° C. (Sept. 8, I961) 



POOLS AND RIFFLES: 



