Geological Survey Bulletin 581—B Oil and Gas in the Western Part of the Olympic Peninsula, Washington

The topography of the area shown on Plate II (p. 78) ranges from flat lands at many places near the coast to mountains 20 to 30 miles inland. The greater part of the area is included in an uplifted, much eroded, and somewhat terraced coastal plain of Pleistocene age, in which swift mountain streams have entrenched themselves. The larger rivers have not only cut through the Pleistocene deposits, which are 100 to 300 feet thick, but have also eroded their channels in the underlying, more resistant Miocene and older formations, whereas the smaller rivers and creeks have not yet cut through the Pleistocene cover. In places along the coast this old plain has been raised above sea level as much as 400 feet, but at other localities the uplift is not so great. The valleys of the larger rivers, the Queets and the Hoh, are marked by at least two prominent terraces. Precipitous cliffs, ranging from 50 to 300 feet in height, are numerous along the coast and at many places along the principal streams. In places the watersheds consist of broad, swampy uplands into which the minor streams have not penetrated, thus suggesting that the topography is still comparatively young. The relief ranges from sea level to 1,500 feet or more at the tops of the high ridges in the vicinity of Queniult Lake on the eastern edge of the area. The terraced lowlands slope with slight breaks from the base of the mountains to the coast, whereas the mountains rise almost precipitously from the floor of the old coastal plain.

In the vicinity of Queniult Lake the topography is typical of that of glaciated areas. In fact, the basin of Queniult Lake itself is believed to be due to a glacier, which emerged from the Olympic Mountains through the U-shaped valley of the upper Queniult River, and which deposited the moraine that now forms the dam at the lower end of the lake. The present topography in the northern and northeastern parts of this field is believed to be partly due to glaciation.