202 



profiles, drawn at intervals of two miles. (Fig. 2.) Tliey are in some 

 places broad, flat and Irregular, but have th-' habit of growing narrower 

 and higher to the south, where they end abrui)tly. Their topography can 

 be shown only l)y a closely contoured niajt, which is in process of con- 



struction but not conii)k'tcd. In the northern part the river edge of the 

 terrace rises 75-80 feet abnvc thmd plain, or lo 535-540 feet A. T. A broad 

 ridge extending sduthward frnii! Atlierton island reaches 550 feet A. T. 



