DRIFT-WOOD ON THE YUKON AND IN BEHRING SEA. 111 



Above the timber layer there is a deposit of silt or clay, and covering this 

 is the peaty layer of the tundra. 



While ascending the Yukon many trees and portions of trees were seen 

 drifting with the current, or stranded on the banks of the river, especially 

 on the upper ends of low islands, and where sloughs leave the main river. 

 At such localities there is not infrequently an acre or two of weather-beaten 

 drift-logs, piled together in a most confused manner and having a depth, by 

 estimate, of fully twenty feet in some instances. The banks of the Yukon 

 and of its tributaries are densely forested, and as they ai'e cut away by the 

 swift currents, furnish an unlimited supply of timber for the river to trans- 

 port. 



The abundance of drift-wood along the banks of the Yukon or traveling 

 with its current explains the source of the many derelicts of the land ob- 

 served during the voyage from Unalaska to St. Michaels. The most of the 

 abundant drift-wood of Behringsea is undoubtedly derived from the Yukon 

 and Kuskokwim rivers. The shores of Behring sea are treeless throughout, 

 but are almost everywhere fringed with drift-wood. The wood thrown ashore 

 by the waves furnishes the only supply of fuel and building material for 

 the natives at widely separated localities, both on the mainland and on 

 numerous islands. At St. Michaels the supply of wood for fuel, both for 

 the residents and for the small steamboats, is gathered from the beach. A 

 large part of the fire-wood used on the steamboats which navigate the Yukon 

 is cut from drift timber. In the sediments now being spread over the bottom 

 of Behriug sea, water-logged drift-wood, principally spruce, must be of 

 frequent occurrence. 



Surface of the Delta. — About forty miles up the river I made a short ex- 

 cursion inland and had an instructive view of a typical portion of the delta. 

 The immediate bank of the river at this point was low and swampy and 

 clothed with a dense growth of alders. The fringe of brush was half a mile 

 broad and terminated landward against a bluff about thirty feet high. 

 Ascending the bluff, I had before me a seemingly boundless expanse of moss- 

 covered land, without a tree or conspicuous shrub to relieve its monotony. 

 Here and there on the dreary moorland were lakelets, frequently circular in 

 outline and surrounded by flowery banks of moss. The soil beneath the 

 thick brown-green carpet was a dark humus, formed entirely from the decay 

 of the tundra plants. The thickness of the humus layer was not determined ; 

 below the depth of about a foot it was solidly frozen. 



The conditions here briefly described continue to characterize the land 

 bordering the Yukon on either hand for a distance of sixty or seventy miles 

 from its mouth. On the right bank the inland border of the tundra is 

 reached a few miles below the village of Andreieflski. The land there rh 

 into hills and the spruce forest begins. The soil is a stiff clay, probably a 

 continuation of the substratum of the tundra. 



