30 TIN DEPOSITS OF THE YORK REGION, ALASKA. [no. 229. 
rated from the Arctic Ocean by a low sand spit, on the seaward side 
of which the shallow water is reported to extend out about 2 miles 
from the coast, so that landing is difficult. For small, flat-bottomed 
boats, however, this lagoon is navigable, and it is possible that such 
boats might, but not probable that they ever will, convey tin ore from 
the Buck Creek mines, out through the inlet, to vessels lying offshore 
in the Arctic Ocean. It is reported that small boats can be brought 
up Mint River and Grouse Creek to within 1 mile of the mouth of 
Buck Creek. These streams, however, are shallow and crooked, and 
it is not probable that they can be used successfully for conveying ore 
from Buck Creek to the sea. 
The plateau already described extends northward from the town 
of York on the coast of Bering Sea to the Arctic Ocean. It has an 
elevation of about 600 feet near York, and slopes to sea level a few 
miles from the Arctic coast. Buck Creek and the other streams in 
its vicinity flow in comparatively new valleys cut in this plateau. 
Above the surface of the plateau there are several buttes, of which 
Cape Mountain and Potato Mountain a are the most prominent. Potato 
Mountain is a large, cone-shaped mountain, having an elevation of 
1,370 feet. From this mountain a range of low hills extends north- 
ward for a distance of 3 or 4 miles toward Lopp Lagoon. 
Buck Creek is a small stream, about 5 miles in length, which rises 
in this range of hills and flows southeastward to (J rouse Creek. Its 
waters are then carried northward through Mint River and Lopp 
Lagoon to the Arctic Ocean. About 1 mile from its mouth Buck 
Creek receives a large tributary from the south, called Sutter Creek, 
and about 4 miles above its mouth it again forks, the two branches 
being known, respective^, as Right and Left forks. Several smaller 
tributaries are received between Sutter Creek and these upper forks. 
The bed rock on which the York Plateau is developed, and in which 
Buck Creek Valley is incised, is a dark, slaty schist, which has been 
alread}^ described. Along Buck Creek it has the characteristic joint- 
ing described in the general discussion of the geology of this region. 
The mountains west of Buck Creek, including Potato Mountain, are 
composed of similar slates. They apparently contain no intrusive, 
igneous rocks, either of the greenstone or granite type. 
Near the mouth of Buck Creek bowlders and pebbles of greenstone 
occur in the gravel deposits. These have not been traced to their 
source, but they probably came from a group of hills on the east side 
of Grouse Creek before the present drainage was established. At a 
number of places along Buck Creek small quartz veins were found 
cutting across the bedding or running parallel with it through the 
slate. Some of these quartz veins are as much as 3 or 4 feet thick, 
a The name Conical Hill was applied to this mountain by Captain Beechey in 1826. It is said to 
have been called " Potato Mountain" by the Russians. On the topographic map, Prof. Paper No. 2, 
PI. XII, the mountain is called "Cone Hill." 
