RECENT DEVELOPMENT OF ALASKAN TIN DEPOSITS. 
By Arthur J. Collier. 
INTRODUCTION. 
The tin deposits of Alaska which give promise of some economic 
importance are situated in what is known as the York region, which 
comprises the western end of Seward Peninsula, though tin in .small 
quantities is much more widely distributed. The tin ore of the York 
region occurs both in lodes and placers, distributed over an area of 
about 450 square miles. Stream tin was discovered in the gold placer 
mines of the Anikovik River, near York, in 1900," since which time 
prospectors have found the ore at many other localities. These 
deposits have already been described by the writer 6 in some detail, so 
that only a brief statement of the geologic conditions is here required. 
During the season of 1904 the writer examined many specimens of 
tin ore and collections of minerals at Nome, made by prospectors who 
were searching for tin in various parts of Seward Peninsula, and later 
spent a few days at Cape Mountain and Lost River, the two points 
where systematic development of tin-bearing lodes was in progress. 
The tin placers of Buck Creek were not again visited, though con-j 
siderable mining was in progress there during the season. It is the 
purpose of this paper merely to describe the developments since 1908. 
LODE DEPOSITS. 
The prospecting and development of mineral-bearing lodes is neces- 
sarily slow and expensive as compared with the rapid development of] 
the placers, and it is scarcely reasonable to suppose that the work 
which can be done in a short Alaskan season will be sufficient to 
demonstrate their value. On the other hand lode deposits have the 
advantage over the placers that they can be worked throughout the 
whole year in Alaska as well as in an}^ other part of the world. Dur- 
ing the season of 1904 development work on tin lodes was in progress 
at Lost River and Cape Mountain, and new discoveries of tin lodes 
were reported at Brooks Mountain, Ears Mountain, and in the Darby 
Mountains, all in Seward Peninsula. These localities will be discussed; 
in the order named. 
<» Brooks, A. H., An occurrence of stream tin in the York region, Alaska: Mineral Resources U. S. 
for 1900, U. S. Geol. Survey, 1901, p. 270. 
& Collier, A. J., Tin deposits of the York region, Alaska: Bull. U. S. Geol. Survey No. 229, 1904, and 
Bull. IT. s. Geol. Survey No. 225, 1904, pp. 154-167. 
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