This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1899 edition. Excerpt: ...has a length of about 75 miles and an extreme width of 50 miles; it embraces not only the White River and some confluent streams, but is extended through to the Tanana in broad, flat valleys. It is interrupted here and there by knobs, hills, and mountain masses, which rise abruptly from the wooded plain. Below this lowland the White has a comparatively narrow valley all the way to its mouth. Where we first reached the Tanana, at the mouth of Mirror Creek, it flows in a broad lowland which might be considered an extension of the valley of the White. The Tanana enters this plain through a narrow gap, above which it has not yet been explored. The river valley here has a quadrangular outline, as will be seen by referring to the accompanying map (No. 9). A study of the map will also show that the Tanana Valley is in fact characterized by a series of these valley lowlands having quadrilateral outlines and bounded by steep escarpments. These broad lowlands are connected by narrow stretches of valley. Below the mouth of the Silokh River the southern side of the valley recedes rapidly, and from this point to the junction with the Yukon it is at least 30 miles wide. Along this lower portion of the river the southern side of the valley is not mapped, but the north slope continues to give suggestions of this quadrangular character in a series of reentrant angles which the river closely follows. Throughout its course the Tanana hugs very closely the north side of the valley. The confluent streams from the north all have sluggish currents and usually deep channels, while those entering from the south are shallow and swift, often being veritable torrents. GEOLOGY. Nasina series.--From the mouth of the White River to Ladue Creek are exposed...