ACTIVITIES 69 



will not obviate the necessity of field examination for classifi- 

 cation. 



As soon as possible after a withdrawal has been made, 

 detailed examination of the withdrawn area is begun. 



The classification of the individual tracts is controlled in 

 large measure by standard regulations previously formulated 

 by the Survey. 



The regulations applying to the several types of mineral 

 land generally define the amount of the given mineral which 

 the tract must be estimated to contain to warrant its classifica- 

 tion as such land. The regulations applying to coal lands 

 necessarily go further and prescribe in the greatest detail the 

 factors to be considered in evaluating such lands. 



The technical methods used in the field examinations made 

 for classification necessarily vary in accordance with the min- 

 eral or water supply whose presence is in question; and as 

 they have been very fully set forth by the Survey in a publi- 

 cation issued in 1913, 12 they will not be described here. 



In general, the results of the Survey's classifications are 

 recorded in such form as to be available only for the use 

 of the Survey, the General Land Office and the Office of the 

 Secretary of the Interior. For its enlarged homestead desig- 

 nations, however, the Survey has printed maps showing the 

 tracts designated. 



As soon as an area has been classified, recommendation is 

 made to the Secretary for the restoration to entry of the 

 lands found not to fall within the provisions of the law. The 

 lands 'falling within such provisions are either restored to entry 

 under those provisions or are reserved from entry under the 

 withdrawal act. 



The classifications made by the Survey are accepted by the 

 General Land Office as controlling, with respect to certain 

 types of classification by order of the Secretary and with re- 

 spect to others by practice. The classification by the Survey 



12 U. S. Geological Survey, Bulletin 537, The Classification of the 

 Public Lands, p. 50 ft. 



