ILLUSTRATIONS. 



Page. 

 Plate I. Sketch map of Alaska, showing distribution of forests, glaciers, and 

 snow fields. (From Professional Paper No. 45, U. S. Geological 



Survey) Frontispiece 



II. Fig. 1. — Western hemlock forest near Ketchikan. Trees range in 

 diameter from 12 to 24 inches and in height from 75 to 100 feet. 

 Fig. 2. — View of Sitka and surrounding forest-covered slopes 13 



III. Fig. 1. — Raft of Sitka spruce logs on beach near Wrangell. Average 



diameter at the butt, 37 inches; at the top, 21 inches. Average 

 length, 78 feet. Contents of raft approximately 190,000 board 

 feet, Scribner scale. Fig. 2. — Raft of Sitka spruce logs shown in 

 figure 1, with general view of shore forest after cutting of raft. 

 Standing timber consists of Sitka spruce, western red cedar, and 

 western hemlock 13 



IV. Fig. 1. — Mixed white birch and aspen forest on sandy slope south 



of Eagle. Timber 2 to 6 inches in diameter, 20 to 35 feet in 

 height. Buildings at Fort Egbert and Eagle Mountain in the 

 background. Fig. 2. — Typical forest on the Yukon flats about 20 

 miles below Fort Yukon on the Arctic Circle. Timber chiefly 

 white spruce, 2 to 8 inches in diameter and up to 50 feet in height; 



some balsam poplar and large willow 13 



V. Fig. 1. — View across Yukon Valley to town of Rampart and hills 

 beyond, from United States Agricultural Experiment Station. 

 Timber mostly cleared and cut. Black spruce at the edge of river, 

 with occasional veteran white spruce. Fig. 2. — Fish and wood 

 camp on the Tanana River near Tolovana. White spruce and 

 white birch cord wood for river steamers has been cut from this 

 forest; balsam poplar and aspen left standing. Fish wheel for 



catching salmon at the right 17 



VI. Fig. 1. — Cord-wood cutting in white birch forest near Fairbanks. 

 Clump of uncut aspen in the background. Fig. 2. — "Wooding 

 up" the engine on the Tanana Valley Railroad near Fairbanks. 

 Remnant of original forest, mostly fire killed 17 



VII. Fig. 1. — Typical mining operation on Engineer Creek near Fair- 

 banks. Small black spruce in the foreground; partially fire-killed 

 birch and aspen on slope in the background. Fig. 2. — Typ ; cal 

 flume and sluice boxes used in placer mining for gold in the Fair- 

 banks district. Much lumber and many poles are required for 

 these purposes 17 



VIII. Fig. 1. — Complete destruction of forest by cutting and fire near Fair- 

 banks. Timber of type shown in Plate VII, figure 1. Fig. 2. — 

 Upper limit of forest on north slope at the head of Cleary Creek. 

 Small black spruce with a maximum height of 20 feet. Elevation, 



2, 300 feet 21 



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