Abstract The Columbia River empties into the Pacific Ocean near latitude 46° N. Much of the detrital load of the river is distributed over a 165 km long littoral cell between Tillamook Head, Oregon, and Point Grenville, Washington. The cell is characterized by north-directed littoral drift in response to dominant southwest winter storms, yet it experiences a summer drift reversal in response to more modest northwest winds and seas. The result has been development of extensive barrier beaches during the late Holocene, which define the major embayments of Willapa Bay and Grays Harbor. The mouth of the Columbia River was modified by jetties beginning late in the nineteenth century. The entrance to Grays Harbor has been jettied since early in the twentieth century. This article discusses changes resulting from these modifications. Dams on the Columbia River and its tributaries built during the twentieth century appear to have significantly reduced the detrital load available to the littoral cell, resulting in the onset of changes in the deposition-erosion regimen.

Abstract The deeply incised central Columbia River valley of Washington State and its tributaries expose mid to late Tertiary basalt flows and clastic sedimentary rocks, pre-Tertiary crystalline bedrock outcrops where the river flows along the eastern slope of the Cascade Mountains between Wenatchee and Chelan. River incision has primarily been driven by the uplift of the Cascades, deposition of the voluminous Columbia River basalts, and the formation of the Yakima fold belt. Glaciation during the Pleistocene, the terminus of which reached Chelan and the northern Waterville Plateau, infused large quantities of sediment into the valley. Concurrently, catastrophic glacial outburst floods, unprecedented in size, repeatedly swept down the river from the north and over the Quincy Basin in the south. Trip stops include some of the early engineering works, principally the dams, where much of the regional stratigraphy was developed and challenging engineering solutions were required for difficult geologic conditions. Stops also exemplify the pervasive large-scale landsliding, common where basalts overlie weak sedimentary rocks. Due to the steep topography, transportation corridors and other developments are widely threatened by rockfall and debris flow hazards. Seismicity is also a regional hazard; the largest historic earthquake in eastern Washington, moment magnitude 6.5-7.0, was sited near Chelan.

Abstract Today, engineering geologists in private industry occupy key positions in the planning, design, and construction of many different kinds of engineering works. Since the beginning of this century, it typically has been the practice of engineering-construction companies to rely on outside consultants for projects requiring geological expertise. However, with the end of World War II and the rapid development of the early 1950s, engineering-construction companies in North America began to hire geologists as staff members. A recent survey of the older major engineering-construction companies by Bechtel (1986) established that about half of the firms support engineering geology staffs in-house, while half rely solely on consultants, either individuals or specialty groups. Furthermore, many of the companies that retain engineering geologists in-house occasionally supplement their staff input with the services of outside consultants for a variety of reasons, including fulfilling contractual obligations, enhancing the work capabilities in a specific geographic area, or reinforcing expert opinions in controversial situations. Today, some of the major engineering-construction companies that support their own in-house geoscience experts include Bechtel Civil, Inc.; EBASCO Services, Inc.; Fluor Engineers, Inc.; Harza Engineering Company; Morrison-Knudsen Engineering Company; United Engineers and Constructors; and Stone and Webster Engineering Corporation. Bechtel was one of the first engineering companies to hire staff geologists. In the early 1950s, they hired Ben Warner, Victor L. Wright, Robert J. Farina, and Charles P. Benziger to work on a project-by-product basis. However, lack of permanent job status and associated benefits, as well as the inability in those days to advance professionally within the company ranks, was not encouraging to the geologists or beneficial to the company, and consequently, many of these geologists moved on to other professional situations.