Water and Ice
Steamboat Rock was once an island in a channel carved by the ancient Columbia River. The river had been forced from its original bed by a sheet of ice moving down from Canada during the last Ice Age, beginning about 18,000 years ago. Ice also blocked the mouth of the Clark Fork River in Idaho, creating Glacial Lake Missoula, a huge body of water that stretched 200 miles into Montana. Eventually, the ice dam holding back Lake Missoula collapsed. A towering mass of water and ice burst through, shooting into and swelling the diverted Columbia in a thunderous rush toward the Pacific Ocean.
This process was repeated dozens of times as glaciers advanced and retreated over the next 2,500 or so years. The powerful floods chewed through the basaltic plains of the Columbia Plateau, stripping away more than 50 cubic miles of earth, gouging deep canyons (“coulees”) in some places, piling mountains of gravel in other areas, and scattering 200-ton boulders all the way from the Rockies to the Willamette Valley in Oregon.
About 13,000 years ago, the ice dam that had diverted the Columbia burst. The river returned to its natural course, leaving behind a bone-dry canyon that was more than 50 miles long, up to 900 feet deep, and, in places, five miles wide. French Canadian fur trappers called it the Grand Coulee, after the French verb couler, meaning “to flow.” At its northern end stood the monolith that came to be known as Steamboat Rock. A “stubbornly uneroded piece of volcanic plateau,” in the words of writer William Dietrich, it was left sitting “like a sternwheeler grounded by a departed tide, silent and evocative as an old wreck” (Dietrich, 28).
Legends of the Flood
Archeologists believe that the first humans arrived in the Grand Coulee area about 11,000 years ago. Indian legends told of a time when the coulee was filled with water and was home to fearsome sea monsters. The canyon walls were said to be stained red with the blood of warriors who lost their lives to the monsters. Early Native Americans avoided the canyon, preferring more hospitable areas closer to the river.
A number of early explorers recognized the Grand Coulee as a former channel of the Columbia. Among them was botanist David Douglas (1798-1834), who explored what he called “a most singular channel ... a wonderful specimen of nature” in 1826. Douglas was certain that the coulee “at one time must have been the channel of the Columbia.” In an aside, he also reported that the canyon’s floor was covered with small pieces of lava and shattered stones, similar to the paving system that had been recently developed in England by John McAdam. “I would advise those who derive pleasure from macadamised roads to come here, and I pledge myself they will find it outdone by nature,” he wrote (Douglas, 208).
Thomas W. Symons, chief engineer of the Army Corps of Engineers, Department of the Columbia, was among the first to associate the coulee with flood waters. Symons surveyed the area in 1879 and 1880. In a report published in 1881, he speculated that the coulee had been clawed out by “a flood of water or ice coming in from the northeast.” He pointed out that “Many rounded boulders are here found in the soil, and great rocks of large size, which could only have been transported by the agency of ice” (quoted in Steele, 524).
Still, it was difficult for most people to imagine that moving water could have shaped the features of a landscape that gets only about seven inches of rainfall in a year. The scientific evidence to support Symons’ intuitive understanding did not begin to accumulate until the 1920s. Even so, it took four decades before the role of water and ice in the geology of the arid Columbia Basin was fully understood.
The key figure in the science of the floods was a young geologist named J Harlen Bretz (1882-1981), whose refusal to put a period after the “J” in his name was just one sign of his willingness to challenge convention. A former high school science teacher in Seattle, Bretz earned a doctorate in geology at the University of Chicago in 1913. He wrote his doctoral thesis on the glacial history of the Puget Sound. After a brief stint as an assistant professor at the University of Washington, he returned to Chicago and joined the faculty at his alma mater. He continued his studies of the geology of the Northwest, and soon built a modest reputation as an expert on stream and glacial erosion.
In 1923, Bretz launched one of the great controversies of modern science by arguing that a sudden, catastrophic flood had created the coulees, gorges, and “channeled scablands” (so-called because they resemble scabs on the back of an animal) of the Columbia Basin. This was a startling departure from the orthodoxy of the time, which attributed the gored and runneled landforms of the basin to the effects of erosion, caused by the gradual advance and retreat of glaciers. That interpretation was based on the principle of Uniformitarianism -- the idea that geological events of the past can be explained by forces that can be observed in the modern world. Since a flood of such vast proportions had never been seen, Bretz’s theory was quickly dismissed.
Bretz did not identify, and initially showed little interest in, a source for the flood. It was another geologist -- Joseph T. Pardee (1871–1960) -- who solved that piece of the puzzle. In 1910, Pardee had documented the existence of an enormous prehistoric lake, created by an ice dam in Idaho, that covered the valleys of western Montana. Pardee speculated as early as 1927 that this Glacial Lake Missoula was the source of Bretz’s flood. But it wasn’t until 1942 that Pardee identified the ripple marks that proved the lake had emptied in a sudden rush to the west. Aerial photography in the 1950s made it clear that the floodwaters that pounded through eastern Washington came from a breach in the ice dam that held back Lake Missoula.
The theory of the Ice Age Floods was refined in later years, as evidence of more than one flood was discovered. It is now well established that Lake Missoula was dammed and emptied numerous times over the course of several millennia. When the dams collapsed, they unleashed some of the largest and most powerful floods in the history of the Earth.
Bretz lived long enough to see his once heretical ideas accepted as the new orthodoxy. Full vindication came in 1979, when he received the Penrose Medal, the Geological Society of America’s highest award, at age 96. He reportedly told his son, "All my enemies are dead, so I have no one to gloat over" (The Tacoma News Tribune, 2005).
Ice Dam Redux
When the first settlers began moving into the Grand Coulee area in the late 1880s, Steamboat Rock was even larger and more imposing than it is today. It reminded Thomas Symons, the engineer who surveyed it in the early 1880s, of “some grand old ruined, roofless hall” (quoted in Steele, 524). Richard F. Steele, editor of a 1904 history of the Columbia Basin, thought it looked more like a battleship. “It stands out boldly, alone, isolated, sharply defined against the uncanny scenery with which it is surrounded, split, hewn off from the adjoining county,” he wrote. “Although destitute of military masts and turrets, the rock is moulded into an exceedingly life-like representation of a huge battleship from stem to stern” (Steele, 594).
The butte stood 1,200 feet tall, measured from its base at the bottom of the then-dry coulee. From a distance, it appeared to be surrounded by water. The illusion was created by deposits of alkali, piled up in dazzling, snow-white beds of soda. During periods of winter rainfall the alkali sometimes retained enough water to form shallow lakes, but the water quickly evaporated. Despite the uncertain supply of water, several homesteaders had established farms around the base of the butte by the early 1900s.
All this changed dramatically in 1951, when water that had been diverted from the Columbia River once again flowed into the Grand Coulee, as part of the Columbia Basin Project.
The project, initiated in the 1930s, replicates with concrete and steel what nature did with ice. Its centerpiece is Grand Coulee Dam, which plugs the original channel of the Columbia River at roughly the same place where an ice dam formed 18,000 years ago. The project also includes four smaller earthfill dams, three storage lakes, hundreds of pumping plants, and thousands of miles of irrigation canals. Two of the dams were built on the north and south ends of the upper portion of the coulee, just south of Grand Coulee Dam. Water is pumped from Lake Roosevelt (the reservoir behind Grand Coulee Dam) into the coulee and from there to smaller storage lakes and canals, for distribution to half a million acres of desert.
Stoppered by dams at both ends, with walls ground down to bedrock by Ice Age floods, the coulee serves as a gigantic and nearly impermeable bathtub for the storage of irrigation water. (The engineers call it an “equalizing reservoir.”) It holds some 1.3 million acre feet of water, in a 27-mile long lake named after Frank A. Banks, chief construction engineer of Grand Coulee Dam.
Steamboat Rock State Park, established in 1972, occupies a 3,522-acre peninsula that juts into the north end of Banks Lake. It includes two campgrounds, a large day-use area, 50,000 feet of shoreline, and habitats ranging from marshes to sand dunes to a pine forest (said to be the only one in Grant County). Sweeping green lawns, watered by automatic sprinklers and protected from winds by tall poplars, provide a dramatic contrast to the arid shrublands near the park. The lake, stocked with hatchery-bred bass and trout, is one of the state’s most popular fishing holes.
Surrounded by water on three sides, Steamboat Rock looks smaller than it once did, but it still dominates the landscape. Red-tailed hawks, northern flickers, and house finches nest here year-round. American goldfinches brighten the spring skies. Large numbers of bald and golden eagles, northern harriers, and numerous species of hawks and falcons can be seen in late fall and winter.
A three-mile hike to the top of the butte provides a panoramic view of the coulee and a glimpse into the geologic and human history of the region. To the north, just over the horizon, lies a great river, swollen with dams but running more or less along its ancient course. Below is the Grand Coulee, cut initially by the diverted river, deepened and widened by subsequent floods, plugged and refilled as part of the largest public works project in the Northwest.
It was the view from Steamboat Rock that planted the seeds for what became the Columbia Basin Project. As early as 1892, local dreamers and schemers began promoting a plan to irrigate the basin with water diverted into the Grand Coulee from behind a dam on the Columbia. The tabletop summit today still offers a perspective on what writer William Dietrich calls “the geographic logic of an idea that utterly changed the Pacific Northwest” (Dietrich, 27).