12 GEOGRAPHY AND GEOLOGY OF RAMPART REGION. 
DRAINAGE. 
The drainage systems are represented on the accompanying map in various stages 
of incompleteness, but with sufficient detail to show their general relations. Tolo- 
vana River, tributary to the Tanana, with its long and widely divergent branches, 
occupies the central and largest part of the field. On the east Beaver Creek in flow- 
ing to the Yukon follows a peculiar V-shaped course between tributaries of the 
Tolovana. On the north and west are Hess and Minook creeks flowing west and 
north respectively at right angles to each other to the Yukon, while in the south- 
west the short irregularly fan-shaped system of Baker Creek carries to the Tanana 
the drainage from the southern slopes of the main divide. 
Tolovana River has several far-reaching tributaries which approach closely the 
Birch Creek and Fairbanks regions on the east and the Rampart region on the west. 
On the north they drain a large area between the systems of Hess and Beaver creeks. 
Chatanika River, which is the most important tributary from the east, has its 
sources far to the northeast opposite the headwaters of Birch Creek. It enters 
the southeastern portion of the area and is closely identified with the Fairbanks 
region since Cleary Creek, an important gold producer, is a tributary. The stream 
is comparatively straight and flows southwest toward the Tolovana. About 50 miles 
below the source, near the mouth of Cleary Creek, it is comparable in size with Little 
Chena near the mouth of Fish Creek, having a width of 100 to 200 feet, and at ordi- 
nary stages of the water it is easily fordable on foot. The valley is open and of low 
grade and the stream keeps mostly to the steep northwestern side. On the southeast 
long lateral spurs from the distant ridges merge gradually into the flat valley. The 
tributaries are small and short. The valleys of those from the northwest are narrowly 
V-shaped; those from the southeast are more open and their stream flats grade 
gently into that of the Chatanika. Sixty miles to the west another tributary of the 
Tolovana, Goose Creek, receives the drainage from the deeply furrowed slopes south 
of Lynx Mountain and flows in a northeasterly direction until it almost breaks in 
upon the tributaries of Hess Creek, when it bends gradually to the south and south- 
west to form an important tributary of the main stream. There are several streams 
between Beaver and Hess creeks, which flow in narrow V-shaped valleys south- 
westward toward the Tolovana. These probably unite to form tributaries of con- 
siderable size before reaching the lower valley. 
The valleys of all the tributaries coalesce finally into a flat which forms a great 
embayment extending northeastward from the river's mouth far into the hill country 
toward the Yukon. The surface of this flat is partly covered with large areas of 
grass and is flecked with lakes, some of which are of considerable size. Patches of 
timber run out into it from the lower slopes of the ridges and dark lines of timber 
crossing it indicate the drainage lines, where streams flow inconspicuously with a 
deep, sluggish current in channels lying 20 feet or more below the even surface. 
Beaver Creek has a peculiar relation to the drainage system of the Tolovana. It 
flows with the tributaries of the latter as if it were one of them and then turns north- 
ward from among them to the Yukon. It heads far to the northeast opposite the 
headwaters of Preacher Creek, flows southwest close along the eastern base of the 
White Mountains in the same direction as the Chatanika, but about 15 miles farther 
to the west, turns sharply round the southern termination of the mountains, flows 
northeast along their western base nearly parallel with its former course to 
Yukon Flats, and crosses this great lowland in a circuitous course north and west to 
the Yukon. The length of the southwestward flowing portion is probably at least 
30 miles; that of the northeastward flowing portion is much greater. The distance 
from the mouth of the creek along the many wanderings across the Flats to the point 
where it emerges from the hills is reported to be nearly 200 miles. Where crossed 
by the Survey party at two localities east and west of the White Mountains the creek 
