Topographic Work of Geological Survey 327 



the summit of the Cascades and the 

 headwaters of the White and Cowlitz 

 Rivers, flowing to the west, and of the 

 American, Bumping, andTieton Rivers, 

 tributaries of the Natches and Yakima 

 Rivers. Mr Sylvester's principal assist- 

 ant will be Mr Ralph Cowgill. 



All the work in the western section 

 is a continuation of the systematic sur- 

 vey, begun several years ago, of the for- 

 ested areas of the Cascade Mountains. 



Oregon. — Topographic work under 

 the direction of Mr Richard U. Goode, 

 geographer, will be continued in Oregon 

 in two localities — one in the eastern por- 

 tion of the state, in the vicinity of Baker 

 City , and the other west of the Cascades, 

 in the vicing of Riddles. 



The part} 7 operating in eastern Oregon 

 will be in charge of Mr C. F. Urquhart, 

 his principal assistant being Mr R. B. 

 Robertson, and will outfit at Baker City. 

 The work will be an extension of the 

 existing triangulation eastward and 

 northward into Union and Wallowa 

 Counties, the object being to provide 

 starting points for future topographic 

 work, which will extend through the 

 forested areas and mining districts. The 

 party will commence work about July i , 

 and remain in the field as long as the 

 weather conditions are such that work 

 can be prosecuted in the mountains. 



In western Oregon one party will be 

 under the charge of Mr A. B. Searle, 

 and will commence operations in the 

 vicinity of Glendale. The work will be 

 in continuation of that commenced dur- 

 ing the past field season, and will result 

 in the completion of the Riddles quad- 

 rangle, comprising an area of about 900 

 square miles. This region is noted for 

 its various mineral deposits, the exam- 

 ination and study of which by Mr J. H. 

 Diller, geologist, will follow upon the 

 completion of the topographic map. 



Another party, under Mr C. H. Sem- 

 per, will be engaged in carrying a line 

 of primary levels from a tidal connec- 

 tion at Benicia, California, along the 



line of the Northern Pacific Railroad as 

 far northward toward Portland as avail- 

 able funds will permit of. Iron bench- 

 mark posts, on which will be stamped 

 the elevation above sea-level to the 

 nearest foot, will be established at all 

 prominent points and at intervals not 

 exceeding three miles. These levels 

 will furnish a main trunk line, from 

 which other lines of levels will ulti- 

 mately branch into the territory to the 

 east and west of the state line, thus 

 furnishing the vertical control for future 

 topographic work 



California. — Under the general direc- 

 tion of Mr Richard U. Goode, geogra- 

 pher, topographic work will be prose- 

 cuted in various localities in California 

 during the coming field season. In the 

 northern portion of the state a special 

 map will be made of the Keswick min- 

 eral region, including an area of about 

 30 square miles. A portion of this area 

 is included in the Redding quadrangle, 

 which has bean recently surveyed on 

 the scale of about two miles to the inch. 

 The special work will be on the scale of 

 about one mile equal to three inches, 

 the large scale being necessary to a 

 proper study of the geologic questions 

 involved in this important district. The 

 party engaged in this work will be in 

 charge of Mr A. B. Searle. 



In the central portion of the state two 

 parties will operate, the areas to be sur- 

 veyed being within or adjacent to the 

 Sierra Forest Reserve. One of the par- 

 ties will be under the charge of Mr R. B. 

 Marshall, who will have as his princi- 

 pal assistants Messrs George R. Davis 

 and L. D. Ryus. The party will outfit 

 at Fresno, and will complete the survey 

 of the Kaiser Peak quadrangle com- 

 menced during the previous season, 

 which includes the upper portion of the 

 San Joaquin River. This party will also 

 extend spirit levels so as to afford verti- 

 cal control for future topographic work 

 in the Mount Silliman and Kings River 

 Canyon region. 



