Development of Engineering Geology in the Pacific Northwest

Richard W. Galster, Consulting Engineering Geologist


Settlement of the Pacific Northwest region of the United States began about the middle of the 19th Century following the Oregon Treaty with Great Britain in 1846. Thus, civil engineering projects began a bit later than did those on the eastern seaboard.

Early engineering projects constructed during the closing years of the 19th Century and the early years of the 20th focused in three areas, routing and construction of roads and railroads, improving navigation into estuaries along the Pacific Ocean coast, and irrigation of dry lands. Little attention was specifically paid to geologic conditions but geology unconsciously must have been taken into consideration even though there is little record of it. There is also considerable evidence that, in many cases, it was ignored. None the less, the development of engineering geology in the Northwest is, as might be expected, tied to the development of civil and military engineering projects required as the region became populated.

Perhaps the earliest systematic feasibility investigations for railroad routing into the Pacific Northwest began in 1853 by government engineers under the command of Isaac I. Stevens, then the first governor of Washington Territory. Two Army officers, Captain George B, McClellan and Lieutenant John Mullan were in charge of these investigations, on the Pacific coast and Northern Rocky Mountains respectively. McClellan later achieved a measure of national fame early during the Civil War. Mullan would later route the first ÒroadÓ into the Northwest across the Northern Rocky Mountains from Ft. Benton, on the upper Missouri River (now Montana) to old Ft. Walla Walla (now Wallula) on the Columbia River in Washington Territory between 1853 and 1862. MullenÕs route crossed the Continental Divide through the Northern Rockies over a nearly 6,000 ft elevation pass. West of the Divide his route followed a section of the valley of the Clark Fork, through the Bitterroot Mountains following a major fault valley to the vicinity of what is now Spokane, thence following a known pack trail to Old Fort Walla Walla. This 25 ft-wide swath, 624 miles long, required hundreds of bridges and numerous ferries across major rivers. In spite of the lack of appreciation for flood stages of rivers and smaller streams, this became the first major route through the Northern Rocky Mountains, later largely followed by U.S. Highway 10 and even later by Interstate 90. The original work was completed at a cost of $230,000!

Major railroad construction did not come until the 1880s and 1890s following the passage of the Northern Pacific Act in 1864 that allowed establishment of the nation's second major land grant railroad. Typical of railroads then, and to some extent now, the focus was on distance and grade, and through route selection was confined to major river valleys that provided reasonable grades, little attention was paid to the importance of geology during routing or construction. Because of the great allowance railroads made (and still make) for continuing maintenance, problems with slope stability and foundations were often solved after construction in a variety of ways including rerouting or adjacent wasting of unstable material as the problems became acute. Short tunnels were commonly constructed through valley side rock spurs or beneath mountain passes as geologic conditions permitted. Some of these had minimal burden and were later converted to open cuts. In some locations original routing that switchbacked over mountain passes was later relocated through tunnels.

Perhaps a civil engineer with some geologic understanding who came into the Northwest in the early days was John Stevens. Stevens established the original and current surface route for the Great Northern (now Burlington Northern/Santa Fe) Railroad through the Northern Rocky Mountains at Marias Pass, Montana. He was also responsible for the routing of that railroad over a series of switchbacks through Stevens Pass in the Washington Cascade Range, routing that later included a 2.6-mile long tunnel that was opened to traffic in 1900. Stevens went on to become Chief Engineer for the Panama Canal between 1905 and 1907, using his railroad experience (and perhaps his landslide experience) in that effort. Stevens was not the only geo-engineering type with Northwest experience to become famous on the Panama Canal. Donald F. MacDonald, a native of Canada, who would later investigate and provide a classic engineering geology analysis of the canal landslide problems for the literature, received his degree in mining engineering from the University of Washington in 1905. MacDonald also spent time doing geological fieldwork under George Otis Smith in Washington and Idaho (Legget, 1993).

Early efforts to improve the navigability of river mouths along the ocean coast also began in the 1880s and focused on the need to maintain channel depths and positions, first at Yaquina Bay and the Coquille River on the central and southern Oregon coast respectively. In 1885, work began on the south jetty at the mouth of the Columbia River. In most cases rubble mound jetties were placed on facine mats in recognition of the mobile sands that were to serve as foundations. Apparently little or no consideration was given to littoral effects along the adjacent coastlines or to the effect of coastal processes on jetty structures. Some jetties were ephemeral owing to lengthy period of construction combined with coastal dynamics. Much of the history of early jetty construction is reminiscent of Kipling's "crab who played with the sea". These have been essentially prototype experimental programs that, over the years, have resulted in numerous redesigns, rehabilitationÕs, and reconstructions requiring upward of 30 million tons of jetty stone along the highly dynamic ocean coast of Washington and Oregon. The jetties have been successful for the purpose intended, but the effects on coastal processes have been far-reaching, some positive and some negative. For example the jetties at Yaquina Bay have resulted in reduction of beach nourishment between the mouth of the jettied harbor and Yaquina Head. The increased sea cliff erosion has resulted in considerable landslide development along this segment of coastline. On the other hand the Grays Harbor jetties have resulted in overall accretion along many miles of beach in both directions owing to seasonal littoral drift reversals.

In addition to the effort to stabilize river mouths, navigation on the lower Columbia and Willamette rivers was of critical importance to early commerce. The earliest lock in the Northwest was constructed at Oregon City on the Willamette in 1873 to permit shallow draft vessels to surmount 40 ft-high Willamette Falls. The lock was originally constructed using private and state funds, sold to the Corps of Engineers in 1915 and rehabilitated by the Corps in the early 1920s. They are still in use.

Where the Columbia River passes through the Cascade Range several major falls and rapids were present that were significant obstacles to early migrants who detoured around the obstructions by land. By the late 19th Century they presented major obstacles to the desire for steam navigation up river from Portland. Between 1878 and 1896 a 3,000-ft-long canal that included a two-chambered lock was constructed at Cascade Rapids. The rather excessive construction period may have been partly a function of the lack of engineering geology. One of the several resident engineers during construction observed "the canal site (to be) exceedingly rough and broken, covered with a mass of boulders varying from one-half to one hundred tons and more in weight." Cascade Rapids lay at the upstream toe of the great Cascade Landslide which was yet to be identified and the work of Bretz in identifying catastrophic glacial flood deposits in the gorge was yet to come.

The remaining major obstacles to navigation on the Lower Columbia were at The Dalles and Celilo Falls. By 1915 the 8.6-mi-long Dalles-Celilo Canal, including five locks, was completed, excavated through flat-lying Columbia River Basalt. There was little question regarding the need for rock excavation, the stability of the raw canal walls or the suitability of the foundations to support lock walls and gates.

Possibly some of the early discussion of geologic conditions and problems related to engineering works in the Pacific Northwest is found in several Corps of Engineers reports to Congress during the first decade of the 20th Century regarding the location of the Lake Washington Ship Canal in Seattle. One route considered was rejected owing to the probable need for rock excavation and excessive siltation from nearby river freshets. Other reports clearly recognized the highly varied nature of the glacial materials including the presence and need to shoot boulders in the "hardpan" (glacial till) and the dredgability of certain lake bottom materials ("ooze"). A 1903 report reflected the keen observations of a young Army officer who casually noted that "it is hard to find areas in Seattle greater than 1-2 miles where sliding (on) clay is not in evidence".It was probably the advent of dam construction for hydropower generation, as well as irrigation, navigation, and flood control that had the greatest impact in the development of engineering geology in the Northwest. During the early days, "natural" (easily evaluated and developed) sites were selected. In 1889 the first hydropower in the region was generated using the available head at Willamette Falls, Oregon and began lighting the nearby city of Portland. Probably the first dam in the Columbia River Basin was built in 1893, a still-operating irrigation diversion weir at Horn Rapids on the Yakima River where the river crosses a resistant basalt flow. The world's first underground hydropower plant was completed during the last year of the 19th Century at Snoqualmie Falls in western Washington. The unsupported and unlined chamber in basalt continues operation to this day. These were more or less obvious sites with sound bedrock foundations.

Congress established the U.S. Reclamation Service in 1902 and established a regional office in Boise, Idaho, which included geologist positions, in 1903. During the first decade of this century several low head dams were constructed on the Snake River in southern Idaho to provide irrigation water to the Snake River Plains. These were long, low-head, diversion structures built on obvious sites where the river formed rapids over basalt flows and reasonable adequacy of the foundation might be assured. During the same period, the first true hydropower dams in the region were constructed at obvious sites on the Spokane River; at Post Falls, Idaho and Nine Mile, Washington; both are still in operation. What geologic analysis may have been done prior to construction of these projects is unknown.

Thus as has been so often the case in the history of engineering geology, the geologists were busy with gaining information on the mineral wealth of the region or waiting around to be introduced, the civil and military engineers were making geologic assessments, some faulty, but many of them quite correct, because the persons making the assessments were good observers in spite of their probable lack of formal geologic training.

One the earliest known engineering geology reports generated in the Pacific Northwest was made in July 1910 by Henry Landes, then Washington's State Geologist, and Milnor Roberts, both at the University of Washington. At the request of the City of Seattle, these gentlemen were asked to report on the feasibility of a dam site in a rock gorge on the Cedar River in the Cascade Mountains east of Seattle. Although Landes and Roberts pronounced the rock in the immediate gorge walls satisfactory, they pointed out that the northeast side of the proposed reservoir wall consisted of open-textured gravel which they recognized as part of a deep morainal fill. They expressed concern for serious leakage around the dam abutment and recommended a testing program to determine the structure and permeability of the glacial fill. The recommendations, though concurred in by a Board of Consultants, were largely disregarded, and the cyclopean concrete dam was built, completed in 1914. Major leakage developed as the initial reservoir was raised and over the next several years test holes were drilled and sealing operations were undertaken. Following a pool raise in 1918 the downstream face of the morainal embankment catastrophically failed, flooding the valley below. Subsequent efforts to seal the reservoir have not been successful and, although the dam is still operational with a reduced reservoir level, it has never been fully operational. Though C.E. Fowler reported on the problem in Engineering News, the geologic causes of the problem did not receive focus until J.H. Mackin's classic paper in 1941.

About the same time as the work on the Cedar, construction of a concrete dam on the Elwha River on the north side of the Olympic Mountains in 1911-1912 encountered different geologic-related problems. The position of bedrock beneath the foundation was never determined. The structure was founded on gravel with only modest attempts to reduce leakage under the dam, and constructed without dewatering or foundation preparation. Following a major failure of the alluvium beneath the dam that allowed the reservoir to empty in about 3 hours, remedial measures that included additional sheet piles, installation of concrete-filled caissons, and upstream fill partly controlled the underleakage, but voids still exist under the structure. This problem was a matter of some discussion as an item in a paper by Charles Terzaghi at the historic 1929 AIME meeting on Geology and Engineering for Dams and Reservoirs. The dam is currently slated for removal in order to permit reestablishment of fish passage up the Elwha River.

Yet some early engineering geology was being accomplished in terms of dam sites. In 1914, eight years before founding the company that bears his name, Leroy F. Harza reported on a Columbia River power project at The Dalles that included a description of the site geology. Over the next several years of the 20th Century's second decade A.J. Collier and Ira Williams reported on the geology of the eastern Oregon Dayville and Clarno reservoirs respectively, H.A. Rands analyzed the difficulty of grouting in volcanic breccia at Estacada Dam, Oregon, and A.P Davis reported on the geologic basis for problems of canal leakage at the Jerome and Deer Flats irrigation projects in southern Idaho as well as the Flathead project in western Montana.

However, during the 1920s there was change in the wind. Two members of the U.S. Geological Survey, Kirk Bryan and Harold T. Stearns, working in the Survey's Ground Water Division under Oscar Meinzer, were sent to the Pacific Northwest to evaluate dam sites for the Federal Power Commission and the Bureau of Reclamation. Bryan's investigations were conducted on the lower Columbia [downstream of the mouth of the Snake River] as well as for the proposed Owyhee Irrigation Project in eastern Oregon. The latter project included reservoir sites, canals and tunnels (the report was not published until 1928 though the field work had been done in 1923-24). Stearns, whose background was in ground water on the Snake River Plains of southern Idaho, (and would later become famous for his ground water work in Hawaii) concentrated his efforts on several projects in southern Idaho, including a proposed dam at Twin Falls, the proposed DuBois Irrigation Project, and the problems of existing Jerome and Blackfoot reservoirs. Stearns ranged into central Oregon to accomplish the first work on dam sites on the Deschutes River and into western Oregon to survey sites on the Umpqua and McKenzie rivers. Years later he would become the chief geologic consultant to Idaho Power Co.

In the spring of 1922 Charles P. Berkey came to Oregon to make a preliminary inspection of dam sites on the lower Columbia River at the request of the Corps of Engineers. He met up with his former assistant Edwin T. Hodge, a graduate of Columbia University, who had recently taken a professorship on the geology faculty at the University of Oregon at Eugene. During the two days they spent together looking at the local geology they were accompanied by two graduate students, Claire P. Holdredge and Ian Campbell. It is likely that both studentsÕ interest in engineering geology was influenced by that encounter.

Between 1910 and 1933 the U.S. Reclamation Service (now US Bureau of Reclamation) constructed seven dams on tributaries of the Yakima River in Washington. Five of these involved the raising of natural lakes impounded behind glacial moraines; embankment dams resting on moraines, each with eventual leakage problems. One dam was a concrete arch structure originally constructed in 1914. Each of these projects had preconstruction subsurface exploration prior to design though the extent to which geologists were used in the interpretation of data in the field is not certain.

One of the worst railroad disasters in the United States history had occurred on the Great Northern mainline west of Stevens Pass in March 1910 when two trains, stalled for 10 days by snow avalanches, were swept off the tracks into the river below killing 101 persons. By the early 1920s the railroad had decided to relocate the line through a longer tunnel and retained George E. Goodspeed a geology professor at the University of Washington to advise them regarding tunneling characteristics. Goodspeed had graduated from MIT the same year as the disastrous avalanche, migrated west to Oregon in 1912 to begin a duel position with the Oregon Bureau of Mines and the Oregon Agricultural College in Corvallis (now Oregon State University). In 1919 he took a position at Washington and with his background in mining engineering was an appropriate choice. The resulting 7.9-mile-long Cascade Tunnel, then the longest railroad tunnel in the Western Hemisphere, was completed in 1929 as continues in use by the Burlington Northern-Santa Fe Railroad.

Two totally unrelated incidents during the late 1920s propelled the development of engineering geology in the Northwest, an activity that began slowly in the early 1930s and continued for the succeeding half century. In January 1927 Congress mandated the Corps of Engineers to survey the entire Columbia River Basin (in the United States) for development of water projects. In March 1928, St. Francis Dam in California failed catastrophically because of inattention to foundation conditions.

House of Representatives Document 308, 69th Congress, First Session, under the provisions of the Rivers and Harbors Act of 1925, had authorized the survey of numerous river basins throughout the United States. The "308 Report" regarding development of the Columbia Basin laid out a multitude of alternatives and included a brief geologic and engineering discussion of each site. Notable contributors to the geologic evaluation of some of these sites were James Gilluly of the USGS, Henry Landes of the University of Washington, together with a graduate student, Howard Coombs, F.L. Ransome, Ira Williams, and Edwin Hodge of the University of Oregon. Much of the field work was done during 1929 and 1930. During the summer of 1931 Hodge conducted a field camp in the Columbia River Gorge and around Mt. Hood mapping the geology of over 2,000 square miles of territory, undoubtedly including the landslides of the gorge (J.E. Allen was one of the students). Much of the attention of the 308 Report was directed to establishing the position of the furthest site downstream (now Bonneville Dam), other sites on the lower Columbia (downstream of the mouth of the Snake River), and the site adjacent to the upper end of The Grand Coulee. The 308 Report recognized the basic foundation conditions at the several sites as well as the significance of major landslides in the Columbia Gorge. Though it was not submitted to Congress until 1934 the geological and engineering work in the federal sector continued. In the private sector, C.F. Tolman of Stanford University reported to Washington Water Power in 1929 on site conditions at Kettle Falls, Washington (now inundated by the Grand Coulee reservoir). Ira Williams investigated potential dam sites on the Lewis River in southwestern Washington. His findings reported to Northwestern Electric Company in 1930 later served as the basis for development of the three Lewis River projects.

Though the Corps of Engineers and the Bureau of Reclamation were already making preparations for Bonneville and Grand Coulee, the first dam on the Columbia was already underway by the time the "308" Report reached Congress in 1934. Stone and Webster Engineering Company designed a low head, run-of-the-river project at Rock Island Rapids on the mid-Columbia and constructed the first stage between 1930 and 1933. In 1929 a report entitled Photographic and Geologic Study of the Rock Island Site, Columbia River was submitted by William D. Shannon, a civil engineer who had been resident engineer on the recently-completed Lower Baker Dam in Washington's North Cascades. The report included a geologic report by Henry Landes, then Washington State Geologist, and some wonderful aerial photography taken personally by the elder Shannon who later was project engineer during construction. (His son, William L. Shannon, would later co-found the first northwestern geotechnical firm of Shannon & Wilson).

The aftermath of St. Francis Dam brought to the attention of engineers the need for constant geologic evaluation of dam sites during both design and construction. As the Corps of Engineers selected the Bonneville site as the furthest practical downstream site, the Corps retained C.P. Berkey to continue as prime consulting geologist. Berkey insisted on sharing these activities with the more available Hodge (there was no cross continental air travel in those days; train was the only way.) Both men convinced the Corps that a full time geologist was needed on the project and proposed that Claire Holdredge be appointed to the post. Thus history was made. The first major dam built under federal auspices on the Columbia River would have a resident geologist. (Actually Holdredge's work appears to have began in 1931 during site investigations.)

Construction of both Bonneville Dam by the Corps of Engineers and Grand Coulee Dam by the Bureau of Reclamation was authorized late in the summer of 1935. Berkey was prime geological consultant for both projects. Holdredge was already at Bonneville. At Coulee, the geological evaluation and mapping of the dam foundation as construction progressed was accomplished by William Irwin and Grant Green under Berkey's general direction between 1935 and 1938. Irwin would later become the Bureau's Chief Geologist.

Meanwhile, in the foothills of the Washington Cascade Range, the Corps of Engineers was getting ready to construct what at that time was the world's highest (430 ft) embankment dam; Mud Mountain Dam on the White River. Edwin Hodge was hired as a geologic consultant. An out-of-work architect by the name of Allen Cary who had taken an interest in geology and had taken formal training at the University of Washington during the mid-1930s, was first hired as a drill inspector and later established the soils laboratory at Mud Mountain. Cary went on to become the Seattle District's first District Geologist, contributing much to the close relationship between engineers and geologists.

The United States went to war in December 1941.

Except for the completion of Dexter Dam in the Willamette Basin of Oregon and LaGrande and Alder dams on the Nisqually River in western Washington, civil works in general and dam construction in particular, were generally placed on hold during the years of World War II. The geologists involved with engineering were serving in the armed forces, or pressed into military geology and other war-effort activities; construction or enlargement of military bases including water supply and natural construction materials. In 1943 the Corps of Engineers, in support of the Manhattan Project (construction of the nuclear bomb), chose the Hanford area in south-central Washington as the site for the first plutonium production facilities. The area was selected on the basis of availability of electric power from the recently-completed Grand Coulee Dam, the availability of cooling water from the adjacent Columbia River, and the small population displacement. Al Cary would later recall his orders to meet Army personnel on top of Rattlesnake Ridge on a certain date, at a certain hour, for consultation relating to geologic matters on an unnamed, high security project. He was able to provide some guidance to the team, but the subject of future radioactive waste and ground water contamination was not discussed, even if appreciated. In the interest of war effort demands the wastes were consigned to below-ground tanks and left for future generations of geologists, engineers, politicians, and lawyers to sort out, a matter of continuing effort to this day!

Following the end of World War II dam construction again began with a vengeance with the attendant need for engineering geology studies both prior to and during construction, and, in some cases, substantial follow-up during operation.

In 1945, the Columbia River Basin in the United States contained 3 dams on the main stem and 20 on various tributaries, all completed during the first 40 years of the 20th Century. During the next 40 years two generations of engineering geologists received their training on investigations, design, and construction of an additional 47 major dams in the Columbia Basin (8 on the main stem in the US) plus 11 more in the Puget Sound Basin of Washington and the Rogue Basin of southwestern Oregon.

The Bureau of Reclamation began construction of the extensive irrigation part of the Columbia Basin Project immediately following the war, work that continued another 40 years. Major players in this effort included Brownie Walcott and George Neff together with a whole team of Bureau geologists, and Fred Jones of the USGS who first analyzed the landslides along the Grand Coulee reservoir.

In 1948 the Corps of Engineers created the Walla Walla District to design the projects on the middle Columbia and lower Snake. C.J. Monahan became the District Geologist and led the work for more than three decades, including some pioneer rock mechanics work. In the early 1950s, Harold Stuart was appointed North Pacific Division Geologist supervising the efforts of three Northwest districts in the development of the Columbia Basin.

Though many of these projects had consultants such as Howard Coombs, J. Hoover Mackin and Harold Stearns, the grunt work was accomplished by the staff engineering geologists in both the public and private sectors. It was a continuing learning experience that included major projects sponsored by Idaho Power Co., Seattle City Light, Tacoma City Light, Puget Sound Power and Light, Pacific Power & Light, Washington Waterpower, and the public utility districts of Snohomish, Grant, Chelan, Douglas and Pend Oreille counties (Washington). The owners involved Bechtel, Harza, and Stone and Webester as major players in their designs. The Bureau of Reclamation and the Corps of Engineers did their investigations and designs in house. In 1964, ratification of the Columbia River Treaty with Canada permitted construction of the Libby Project on the Kootenai River in northwestern Montana that included the 6.9 mile-long Flathead [railroad] Tunnel, and permitted major modifications to Grand Coulee, Chief Joseph, Rock Island, and Bonneville dams on the main stem. Three major dams were constructed in British Columbia as a result of the treaty.

In addition to the dam construction, the post-war influx of population into the Pacific Northwest increased the need for additional water supply and transportation routes. By the late-1950s, partly as an outgrowth of the funding made available through the interstate highway system, engineering geologic work on transportation routes (though the terms geologist or engineering geologist were rarely used; materials engineer or technician were common) was common in all four northwestern states. Solving the problems of waste management also required engineering geology expertise, especially in the major metropolitan areas. The development of ground water to supply the population was also becoming commonplace resulting in increased knowledge of Northwest aquifers and the need for safeguards and conservative use, unheard of during the war years. This gave rise to a number of firms that specialized in hydrogeology.

Although the term geotechnical had yet to be invented, the consulting engineering firm of Dames and Moore had migrated north from California to establish Northwest offices, and in 1954, the home-grown soils engineering firm of Shannon and Wilson was founded in Seattle. Geotechnical engineers and engineering geologists who received their training in these two firms during the late 1950s and early 1960s went on to found more than a dozen geotechnical companies in the Northwest during the succeeding two decades. The Corvallis engineering firm of CH2M was established. During the early 1960s Ken Dodds founded Foundation Sciences in Astoria, Oregon, later moving the headquarters to Portland. Some of the increased workload was a direct function of the cold war. Numerous Aircraft Control and Warning (AC&W [radar]) stations were established through all four northwestern states as part of the NORAD defense effort. NIKE ground to air missile sites were established. As the nation developed the concept of the intercontinental ballistic missile (ICBM) a considerable amount of geotechnical effort was expended, first on the Atlas system, then on the Titian system and finally on Minuteman. Engineering geologists and geotechnical engineers were usually included as members of siting teams, and an impressive horde of their compatriots from both government and private sectors were marshaled for site evaluation including the search for water supply and construction materials. By the mid-1960s this work was over. By the late 1960s focus of the Defense Department was on ABM (Anti-Ballistic Missile) schemes, first Sentinel and later, Safeguard. The latter program was cancelled just as construction was getting underway.

During the late 1960s engineering geology activities on the Hanford Reservation began to awaken. The first engineered facility not dedicated to plutonium production (the Fast Flux Test Facility [FFTF]) required geotechnical site evaluation. This was a portent of what was to come during the 1970s which may be aptly termed the nuclear power plant decade.

On the professional side: By the early 1960s the number of practitioners in engineering geology in the Pacific Northwest had grown to the point were some type of organization seemed appropriate. Cooperation between practitioners in the public and private sectors had spurred much of this interest. Neither the Northwest Mining Association nor the loosely organized Northwest Geological Society seemed the appropriate vehicle. In the spring of 1963 a group of engineering geologists in the Puget Sound Basin, knowledgeable of the California Association of Engineering Geologists who had recently dropped the state name, petitioned AEG to form a section in Washington, the first outside California. The AEG Board approved the petition in June 1963. Two years later a similar group in Portland, Oregon organized the Portland (now Oregon) Section. In 1968, the first AEG annual meeting was held in the Pacific Northwest (in Seattle) and in 1971, the Portland Section sponsored a meeting in that city. The Washington Section began efforts to obtain licensure of geologists in 1965, but was not successful until 2000. Oregon and Idaho approved licensing laws during the 1970s. Montana has yet to make a serious move in this direction.

Beginning in 1968 work was underway for the Trojan nuclear power plant (Oregon's first and only) on the Columbia River near St. Helens, Oregon. The plant was completed in 1973. In 1971 and 1972 the initial siting work for Washington State's first nuclear power plant was undertaken on the Hanford Reservation. Within two years investigative work had begun on WNP 1 and WNP 4 at Hanford, WNP 3 and WNP 5 at Satsop in southwestern Washington, and the Pebble Springs nuclear site near Boardman, Oregon. Portland General Electric sponsored the Oregon projects; the Washington projects by the Washington Public Power Supply System (WPPSS; later known as "woops"!). An eighth project sponsored by the Puget Sound Power and Light Co. in the Skagit Valley of northwestern Washington also created considerable investigative activity for several years. It was eventually resited to the Hanford Reservation and later cancelled before licensing. Neither the Idaho nor Montana power companies succumbed to the nuclear power effort, both being content with hydropower plus a large coal-fired plant in the southeastern part of Montana. Construction of WNP 2 began in 1972. The project was not completed for 12 years. In the meantime the Trojan plant was completed and placed in operation. Three plants were abandoned during construction; the others were abandoned before licensing. The Trojan Station was shut down in the late 1990s and the Columbia Power Station (WNP 2) at Hanford remains the only operating nuclear power station in the Pacific Northwest.

The problem seized upon by the interveners was not one of foundation stability assessment, but one of seismic design, augmented by rapidly developing concepts of plate tectonics and its influence on engineering seismology. Although important earthquakes were experienced in western Washington in 1872, 1949 and 1965, and in the Northern Rocky Mountains during the mid 1930s and in 1959, paleoseismic studies had really not yet begun. It might well be said that earthquakes in the Pacific Northwest were invented during the late 1960s and early 1970s in response to the needs required for nuclear power plant design. However, the Byzantine licensing process essentially eliminated further construction of nuclear power plants in the Pacific Northwest. The billings for geotechnical costs to say nothing of the legal costs were staggering. Tilford (1978) recorded geotechnical billings of $ 2.3 million for a single Pacific Northwest plant in 1973 alone. The nuclear power plant activity brought numerous geotechnical firms and independent engineering geologists and geotechnical engineers into the Northwest in unparalleled numbers for periods of a few hours to several years. It became apparent that there were a great many unknown experts in Northwest geology, seismicity and tectonics. Much of this was also precipitated by licensing requirements, originally by the U.S. Atomic Energy Commission and by its successor, the Nuclear Regulatory Commission. Ultimately, some sites became research projects instead of engineering projects, a problem that would eventually carry over into the question of the disposal of nuclear waste.

The focus on appropriate seismic design brought to fore by the nuclear power licensing requirements together with the passage of the National Dam Safety Act in 1972 splashed onto the dam design and construction effort throughout the Northwest. During the late 1970s and early 1980s, and even continuing into the early 1990s, all federal dams and major private dams were reviewed for seismic and hydraulic safety. The review and, in many cases, modification required additional engineering geology expertise.

The 1976 failure of Teton Dam on the Eastern Snake River Plains of Idaho rudely brought to our attention the results of not making engineering geology a continuing and critical part of the design and construction process. A considerable effort was made during the late 1970s to understand the causes of the failure.

With the demise of the nuclear power industry, some geotechnical firms who had established offices in the Northwest to be involved with that industry folded their tents and moved out, or at least moved their engineering geology staffs elsewhere. A few maintained some presence however. By the mid-1980s, many of those remaining had moved into the rehabilitation of contaminated ground and other matters of waste disposal.

The eruptions of Mount St. Helens in 1980 brought several years of engineering geology work, both in the clean up effort and construction of facilities to control future flooding and debris flows from the volcano. In addition, the volcanic hazards of the Pacific Northwest received much more deserved attention from the engineering community.

There remains continued geotechnical work in terms of project foundations, landslide mitigation, ground water management and other classic engineering geology activity. Paleoseismicity remains a subject of continued research, but pending the advent of major projects, the engineering geology community has left much of the paleoseismic investigation to the academic community and the USGS. There remain questions to be answered in the clean up at the Hanford Reservation in the Pasco Basin, as well as at the Idaho National Engineering Laboratory on the Eastern Snake River Plains. And there is considerable work to be done in dam safety and understanding the conservative management of ground water aquifers.