1934 ] 
Mosquito Investigations in Alaska 
203 
Fairbanks Exploration Company, has described the general 
region as follows : 
“The region may be described as a plateau, with bed rock 
composed predominantly of schists, which has been cut by 
numerous streams and their tributaries. Comparatively 
broad unsymmetrical valleys with broad interstream areas 
are characteristic. Isolated prominences, locally known as 
Fig 4. Characteristic view of country in the region where mosquito 
investigations were made 
domes, which are composed of igneous rocks and owe their 
presence to the resistance of such rocks to weathering, rise 
above the general level of the neighboring ridges (Fig. 4). 
The average elevation of the ridges is around 2000 feet above 
sea level, while that of the valleys varies from 470 feet at 
Fairbanks to 940 feet in the valley of Goldstream at 
Gilmore.” 
“The region has been subjected to long continued and in- 
tricate stream modeling and since it lies outside the area of 
