Thousands of years ago, glaciers roamed the earth. “The sheer weight of a thick layer of ice, or the force of gravity on the ice mass, causes glaciers to flow very slowly. Glaciers periodically retreat or advance, depending on the amount of snow accumulation or evaporation or melt that occurs. Alternatively, glaciers may surge, racing forward several meters per day for weeks or even months.”1
“The Puget Sound is part of the larger geologic province of the Puget Lowland. Both were sculpted by the thick and extensive glaciers that advanced south to just beyond Olympia. Glacial till (sediment deposited directly by the ice) and outwash (sediment deposited by meltwater in front of the glacier) make up most of what is found at or near the surface. These glacial sediments were deposited during the last 2 million years by numerous glacial advances, the most recent of which was around 15,000 years ago.”2
|“The Vashon Stade, part of the Fraser Glaciation was the latest major incursion of ice into the Puget Lowland. Ice advance as south as Tenino, WA, and was upward of 4,200 feet thick in the northern Puget Lowland.”³ Remnants of Whidbey Island’s glacier-covered past appear in several ways, including through a large concentration of kettle formations near Coupeville.|
“Glacial kettles are small depressions that form when a retreating glacier leaves a bit of ice behind which then becomes buried by sediment shed from glacial streams. When the block of ice melts, the ground collapses, forming a kettle.”⁴ In 2005, the Washington Department of Natural Resources published a geological map of Coupeville created by Michael Polenz, Stephen L. Slaughter, and Gerald W. Thorsen with a level of detail about Pleistocene and Holocene deposits to make a non-geologist’s eyes bleed (so be careful). In addition, 20′ contour intervals clarify the locations of at least a dozen of kettles within Fort Ebey State Park/Kettles County Park. Storms during the winter of 1990-1991 exposed fossils within a kettle at Partridge Point (indicated by the encircled number two on the map), “With the exception of Ursus americanus (Black Bear) skeletons discovered in a cave on Vancouver Island…Cedar Hollow contains the only known early Holocene paleofauna west of the Cascade Range…[they] show that the ecosystem that developed within 2,000 years following deglaciation was populated by many species that presently inhabit the region.”⁵
“The final retreat of the Cordilleron ice sheet was accompanied by the extinction of most large mammals, and the Cedar Hollow paleofauna provides evidence of repopulation of the region. Although [the Gray Wolf] and [Brown Bear] were driven to extinction during the past century by humans, and [the Meadow Vole] no longer resides west of the Cascade Range, all other Cedar Hollow fossils are from species that still inhabit coastal Whidbey Island.”⁵
This winter, after several summertime runs along a fraction of the 35 miles of trails of the Kettles Trails system, I still had no idea how to identify a kettle, so I set out to do so in preparation for the Fort Ebey Kettles Trail Run, held the last weekend in February. The half marathon with 2,800′ of climb and the full marathon (two loops of the half course) took place on Saturday, February 23, 2019 followed by a 5K and 10K, with 660′ and 1,320′ of climb, the following day. In order to avoid competing against, likely losing to and having to shove the face in the dirt of my mostly faster sister, I decided to sign up for the 5K after she chose the 10K. Between the four events held in two days’ time, 500 runners traversed 5,700 miles of mostly single track trail, encountering several kettle formations in addition to awesome views of the Olympics and the Salish Sea. I was disappointed to learn on race day that my decision to hit the easy button meant I’d miss out on seeing Cedar Hollow. In spite of the cold and clouds, both my sister and I loved our respective routes and were surprised at the amount of climb in an area that doesn’t rise much higher than 200′ above sea level.
Days later, I returned for more, parked near the gun battery and headed south along the bluff trail. As I descended along the Cedar Hollow Trail, I hoped that I might end up near the beach, but even at its lowest point, it was way too dangerous to do more than look longingly at the eroded bluff. Fortunately, a local hiker arrived in time to help lift my spirits by insisting that I visit Cedar Grove. The cedars were spectacular, but that wasn’t the best part: this kettle was so conspicuous that even a person who had no clue could see that she was descending into an enormous, oddly shaped, high-sided bowl. The second best part was that I didn’t encounter another soul on my return route to the parking lot when I followed Kettles Trail, Forest Run, and Campground Trail. Next I headed north to visit Lake Pondilla (filled with shorebirds) and the nearby beach. I happened to arrive during high tide, which prevented me from walking to Cedar Hollow along the shore, but I spied a pair of Harlequin ducks and two seals that submerged a couple of times and then disappeared, which made the beach trip worthwhile.
Now that I know how to identify a kettle, I can’t wait to return (again and again) to traverse more of the trails, check out the trees and think about what life might have been like when bears and wolves roamed Whidbey Island.
- National Snow & Ice Data Center All About Glaciers
- Washington State Department of Natural Resources (WSDNR) Puget Sound and Coastal Geology
- WSDNR The Cordilleran Ice Sheet
- WSDNR Glacial Landforms of the Puget Lowland (pdf)
- Mustoe, George E., et al. “CEDAR HOLLOW, AN EARLY HOLOCENE FAUNAL SITE FROM WHIDBEY ISLAND, WASHINGTON.” Western North American Naturalist, vol. 65, no. 4, 2005, pp. 429–440.