452 /. HARLEN BRETZ 



Inlet by a group of high hills of igneous rock. North of them the 

 prevailing meridional orientation again occurs, and in the southern 

 portion of one such trough, Dogfish (Liberty) Bay lies today. This 

 till trough continues north across the peninsula to Hood's Canal with 

 a swamp col near midlength 120 feet A.T. Here then was a pass 

 lower than the Chfton outlet, and with its exposure the level of the 

 ponded glacial waters fell and the Clifton channel was abandoned. 



The Poulsbo channel, the outlet from Hood's Canal to Dogfish 

 Bay, has valley sides that rise to an altitude of 200 feet above the col. 

 A definite stream floor fragment lies on the east side of the summit, at 

 about 150 feet A.T. 



At the mouth of the Dusewallips River which enters Hood's 

 Canal from the Olympics, occurs a portion of an ancient delta of 

 that stream, the seaward front rising quite steeply from marine water 

 to an even crest of 120 feet. It lies on the north side of the valley 

 mouth, the form and extent being well shown in 20-foot contours on 

 chart 6,450 of the U.S. Coast and Geodetic Survey. Save for one 

 post-glacial ravine, no break occurs in the plane surface which reaches 

 back at least two miles with an almost imperceptible slope upstream. 

 The surface of the plain is everywhere of sand and stream-rolled 

 gravel. Obviously this delta correlates with the 120-foot level of 

 the Poulsbo channel. The significance of the 120-foot level and of 

 the 150-foot terrace in the Poulsbo channel will be discussed later. 



GLACIAL LAKE OF PUYALLUP VALLEY 



One of the larger meridional troughs of the region lies parallel 

 to Admiralty Inlet on the east. It is occupied in its northern extent 

 by Lake Washington and, retaining its character of a till trough, 

 reaches as far southward as Orting. Originally an arm of the Sound, 

 post-glacial alluviation has silted it up. The most southern break in 

 the valley walls is at Tacoma, and the topographic conditions south 

 of this are such that a local glacial lake must have existed in the valley 

 early in the final retreat. This portion of the trough is properly 

 termed the Puyallup Valley. 



The only known record of the Puyallup glacial lake is its outlet 

 valley. In this valley lie Lake Kapowsin and Ohop Creek. A col 

 just south of Lake Kapowsin causes a small stream entering there 



