and mapping of the gold, silver, and coal-bearing rocks of Colorado, Utah, Wyoming, Idaho, and Montana, and, if feasible, to begin work in Arizona and New Mexico. In this connection detailed studies will be made of such typical mining districts as will throw light upon and aid in the development of similar districts elsewhere. 8. The Pacific slope: The mapping and study of the gold belt of California has been greatly advanced, but a number of years will be required to complete it, and this will be one of the essential features of the work in this region. Areal work will also be continued in southeastern Oregon; and it is planned to begin the mapping of the coal areas of Washington, and the study of the coal resources of the Pacific slope. 9. The interior southwest and the region of the Great Plains, from the Rio Grande to the British boundary. In this broad area special attention will be given to areal mapping, and also to the mineral resources in coal, iron, lignite, cement clay, building stones, the occurrence of artesian water, etc.
The resources of the interior Mississippi basin are more generally known, and the work there will be of a special character, or in co-operation with State surveys.
The investigation of the water resources of the arid and semiarid regions and of the country at large will be systematically carried forward until the available water supply from every artesian source and from every stream in the United States is accurately known, both for irrigation and power. This project, if carried out, will cover a number of years, and it will doubtless repay the outlay in the assistance it will give to the development and prosperity of all sections of the country.
If the proposed amendment relating to the geology of highways is adopted by Congress, material entering into road construction will be obtained by field parties of the survey and also through State surveys, road commissioners, and individuals; and tests will be made to enable all who are engaged or interested in the construction of highways to make an intelligent selection of materials to be used. It has been said that the status of a nation's civilization may be estimated by its facilities of communication within its own borders. Believing this to be true, the policy of the Geological Survey will be to assist in perfecting all roads by addressing itself to the purely geologic question of choice of materials entering into their construction.
The investigation of the phenomena of the great ice invasion of the north will be continued until all of its important features have been studied and interpreted, and the formations resulting from its influence, direct and indirect, have been determined and mapped.
It is also proposed to co-operate with individuals and State
