On the Trail of the Ice Age Floods: The Northern Reaches
Introduction“Unparalleled in the whole wide world, scarcely even approached by any landscape of similar origin, are the Channeled Scablands on the Columbia Plateau in eastern Washington.”
– J Harlen Bretz (1959)
Clues to repeated decimations by colossal Ice Age floods are written all over the landscape of the Pacific Northwest. The paths of the Ice Age floods in northern Idaho and the Channeled Scabland, the features they left behind, and how to recognize them are the subjects of this book. The Scabland is of special significance because it inarguably contains the most dramatic and impressive evidence for flood erosion anywhere in the world. Part I of the book introduces readers to the floods and provides a primer on how to identify specific flood features. Sixty-five of the most significant features in the Scabland (see page 23), including those found in Grand Coulee, Moses Coulee, the Cheney-Palouse and the Telford-Crab Creek scabland tracts are described.
Also included are several spectacular overlooks at Riddle Hill, Steamboat Rock and Dry Falls where one can see multiple features while taking in a broad view of the floods’ path of destruction. For ease of understanding, features are segregated into seven specific geographic regions of eastern Washington and northern Idaho. The discussion of features starts with the area of ice-dam breakout within the Rathdrum Prairie-Spokane Valley. From here we follow the floods downstream through the Spokane and Pend Oreille river valleys before they spilled over into the Cheney-Palouse Scabland Tract, Telford-Crab Creek Tract and Grand Coulee. Finally we present two other areas impacted less frequently by Ice Age floods – Moses Coulee and the Columbia River valley along the western margin of the Columbia Plateau.
Because the best way to understand and appreciate the Ice Age floods is to get out and immerse oneself in the landscape, Part II provides trail and tour descriptions along with more detailed maps. Readers can discover the aftermath of the floods firsthand in a variety of ways, depending on time, physical ability and budget either by: non-motorized trails on foot, mountain bike or horseback; public roadways via automobile or bike; watercraft through innumerable lakes and waterways; or aircraft.
Although individual flood features rarely provide conclusive evidence for large-scale floods, when examined collectively, they tell an amazing tale of repeated cataclysms. Join us in discovering, firsthand, the wild landforms left behind by the Ice Age floods, much as they existed when legendary geologist J Harlen Bretz unraveled this amazing geologic tale early in the 20th century. Our geologic heritage, no less important than our valuable cultural heritage, belongs to all of us. And, like artifacts, many flood features are threatened by development. It is the authors’ wish that, by drawing special attention to these awesome and often unique features, they may be preserved for future generations to enjoy and appreciate. An important step in that direction was taken in 2009 by the U.S. Congress when it approved legislation to establish an Ice Age Floods National Geologic Trail (see sidebar, page 21).
Locations of 65 major flood features within the Channeled Scabland and adjacent areas. The braided paths of the floods are apparent from outer space where the floods completely removed the loose, light-colored Palouse topsoil, eroding down into the underlying dark basalt bedrock. Each numbered feature is identified in the table of contents and further described in chapter 3. Flood features downstream of the Channeled Scabland, within the Mid-Columbia Basin, are covered in volume 1 of On the Trail of the Ice Age Floods, published in 2006.
“No one with an eye for landforms can cross eastern Washington in daylight without encountering and being impressed by the ‘scabland.’ … The region is unique: let the observer take the wings of the morning to the uttermost parts of earth: he will nowhere find its likeness.”
– J Harlen Bretz (1928)
Located following page 338 in this guidebook are 32 pages of color plates that illustrate with pictures, aerial photographs and maps some of the most visually striking features and landforms of the Ice Age floods. In general, the plates are arranged geographically starting with the outburst area for the Missoula floods and progressing westward through the Channeled Scabland.
Chapter 1 provides introductory and background information on floods responsible for the Channeled Scabland, beginning with hundreds of hot, burning flows of molten basalt lava that flooded the region 17.5 million to 6 million years ago, long before the first Ice Age floods. The volcanic lava flows form the canvas on which the floods painted an intricate tapestry of landforms. A primer of Ice Age flood features follows in chapter 2 where each of the 18 major types of flood landforms is explained and illustrated in more detail. Chapter 3 provides more detailed descriptions for 65 selected flood features within the flood-breakout zone of northern Idaho and the Channeled Scabland of eastern Washington. While many more floods features exist, we have chosen a subset that we believe best represents the range and diversity of flood-borne features. These include landmarks directly created by outburst floods (e.g., Rock Lake, Steamboat Rock, Pangborn Bar) as well as some features that did not come in direct contact with floodwaters, but played an instrumental role in determining the relative timing and paths for hundreds of separate flood events (e.g., Hoodoo Channel, Withrow Moraine). Undoubtedly, covering such a large area, the authors have missed some important flood-related sites. Readers are encouraged to suggest areas to include in future editions or supplements to this publication.
Part II presents trails and tours within the floods’ terrain, designed to lead readers into the field to discover the story of the Ice Age floods and its matchless features for themselves. Directions and the geologic highlights of more than 40 non-motorized trails on publically accessible lands are presented in chapter 4. The five road tours in chapter 5 are designed to cover the greatest number of interesting flood features in the least amount of distance and time. Readers who want to create their own auto-tour routes can do so by linking any of the roads and features herein. Because of the floods’ huge scale, aerial tours in chapter 6 are ideal for those who want to take advantage of two customized routes that provide a vantage point to more fully envision the “big picture” of the floods.
The conclusions and interpretations presented herein build upon almost 100 years of research performed by dozens of other scientists. At the end of the book is an exhaustive list of references, both technical and non-technical, that are the scientific foundation for this book. Finally, located at the very back, is a glossary of geologic and other terms that may not be familiar to the general public for whom this book is designed.
“The physiographic expression of the region is without parallel; it is unique, this channeled scabland of the Columbia Plateau.”
– J Harlen Bretz (1928)
In this age of rapid change, it’s good to know there are places on Earth that have not changed much since the West was settled many decades ago. This is true of much of eastern Washington. Traveling through the Channeled Scabland is like going back in time where you can explore places such as Krupp, Bluestem, Ewan and Stoner. These communities have not changed appreciably since the 1920s when Bretz first combed the countryside piecing together his “outrageous” hypothesis for a Spokane Flood. Come enter this unique landscape and discover for yourself the wild and peaceful solitude of the Channeled Scabland.
Nonfiction. 480 pages, 6" x 9" inches softcover, 400 black-and-white illustrations, maps and photos, 50 color plates, index