LETTER OF TRANSMITTAL. 
Department of the Interior, 
United States Geological Survey, 
Washington, D. C., March 0, 190 %., 
Sir: I have the honor to transmit herewith a report entitled "The 
Tin Deposits of the York Region, Alaska," by Mr. Arthur J. Collier, 
and to recommend its publication as a bulletin. 
Placer tin was discovered in this region in 1900, and since that time 
active prospecting has been going on to determine the extent and dis- 
tribution of the stream tin, and also to locate its source in bed rock. 
Though the occurrence of tin-bearing lodes had been previously 
reported, the first authentic discovery of this kind was made by Mr. 
Collier during the last season, and this find has awakened great inter- 
est in the district. The demand for authentic information regarding 
these occurrences has led to the preparation of this report, which is 
based on a very hasty field examination. The aim has been to sum- 
marize all the information in regard to the occurrence of tin which 
might be of value to the prospector, and for this reason a brief descrip- 
tion of the better known tin deposits of the world has been included. 
The publication of the geologic results of these investigations is deferred 
until a more complete study of the notes and specimens has been made. 
Veiy respectfully, 
Alfred H. Brooks, 
Geologist in Charge of Division Alaskan Mineral Resources. 
Hon. Charles D. Walcott, 
Director United States Geological Survey. 
