From letter of transmittal: The report contains 63 contributions from 37 members of the Survey who have been engaged more or less continuously throughout the year in economic work, together with brief statements by the geologists in charge of the section of metalliferous ores and the section of nonmetalliferous economic minerals, of the extent and character of the economic work being carried on in the Survey.

From letter of transmittal: This manuscript is based on geologic and topographic reconnaissance survey, made during the summer of 1903, of an important placer-gold district in the northeastern part of Seward Peninsula.

From letter of transmittal: This report contains the economic results of a reconnaissance of these gold fields of the Yukon basin which was carried out in 1903.

From introduction: This report is a summary of the present knowledge of limestone beds in southwestern Pennsylvania.

From letter of transmittal: It is believed that this report will stimulate the mining industry by making available, in compact form, the accumulated results of the experience of mining men in this field and by directing attention to those mining methods developed in older districts which appear to be adapted to the conditions prevailing in Alaska.

From introduction: This report is made in response to a general demand for information a reconnaissance of the petroleum and coal fields in the vicinity of Controller Bay and Bering River and of the petroleum fields on the west shore of Cook Inlet and at Cold Bay made during 1903 and 1904.

From introduction: The observations recorded in this paper were made during a rapid reconnaissance from east to west through the central part of Oregon in the summer of 1903, and are in continuation of similar work in the same general region previously done by the author, reports concerning which have been published.

From letter of transmittal: The report contains fourteen papers, prepared by ten members of the geologic corps, who have been engaged in Alaskan investigations during the last year. In this report an attempt has been made to summarize the economic results of last season's field work. Geologic matter has been entirely excluded, except where it has a direct bearing on the subjects under discussion. While such a report can have no permanent value, other than as a record of mining conditions during the year, it is believed that its prompt publication will help the mining industry of Alaska.

From introduction: This report contains papers on summaries of progress in various phases of the mining industry during the last year, preliminary accounts of investigations in progress or completed, and statements of the results of minor investigations not to be published elsewhere.

From introduction: The subject of this paper is the district of the extreme northwestern portion of Illinois, included in the upper Mississippi Valley containing zinc and lead.