Category: Street-Smart Naturalist Blog

My wife and I recently visited Seattle’s wonderful Museum of History of Industry (MOHAI), which houses a stunningly cool model of the Seattle landscape. The model, on the second floor, illustrates how the topography of Seattle has been shaped over time. It is the most clear illustration of the incredible changes that have taken place in the city over the past 150. The shots that I include focus on the south end of downtown.

Photo one shows Elliott Bay and the tidal flats of the Duwamish River around 1851, the year the first large party of settlers arrived in Seattle. The key is to note where the Duwamish River enters the bay and the several islands at its mouth. What is not shown clearly is the vast tidal flats, half the day under water and half the day an expanse of aromatic mud, that covered around 1500 acres. Beginning almost immediately, Seattleites began to dump material, such as sawdust and trash, onto the flats. In 1895, wholesale filling of the flats began when ex-governor Eugene Semple organized the Seattle and Lake Washington Waterway Company. Over the next 20 years almost 90 percent of the flats were filled, primarily with silt and sand dredged from the flats, but also with fill washed off of Beacon Hill and from the Jackson Street and Dearborn Street regrades.

Photo two shows the new landscape dropping in.

Photo three shows the post fill landscape, including Harbor Island, which was finished in 1910 and became the largest man-made island in the world.  (There is some debate about when Harbor Island was completed. I chose 1910 based on newspaper stories.)

 

Just a short announcement about three upcoming walks and talks: two by me and one by my pal Dave Tucker.

September 28 – all day – The Seattle Street Smart Naturalist – You don’t have to drive to the Cascades or take a ferry to the Olympic Peninsula to engage your connection with the earth — even in the heart of the Emerald City, we are surrounded by nature. The day will begin beneath the Magnolia Bluff, the perfect spot for seeing coastal geological processes. We’ll proceed along the Duwamish River, where we’ll read the record of Seattle’s most active earthquake zone. Next we’ll head to Pioneer Square to start a two-mile-long transect to investigate 330-million-year-old fossils and see where mammoths once roamed. This program is presented by the North Cascades Institute. Cost $95.

September 28 and 29 – all day each day, same class each day – Mount Baker: The Story of Volcanoes – Experience time travel by foot on the Ptarmigan Ridge trail in Mount Baker’s radiant late-summer high country. Our field excursion with instructor Dave Tucker will begin above tree line at Artist’s Point at the end of the Mount Baker Highway before venturing out toward the simmering, glaciated volcano herself. Along the way, we’ll travel over ancient records of volcanism as we traverse the 1-million-year-old Kulshan caldera, a giant volcano that erupted cataclysmically through a continental ice sheet long before Mount Baker built itself from stacks of lava.

As we hike past lava domes that erupted shortly after the caldera collapsed, we’ll lay hands on much younger columnar andesite that still predates Mount Baker, discuss the origin of the eroded table at Table Mountain, and examine layers of volcanic ash preserved in the soil, including the famous Mount Mazama/Crater Lake layer. This program is presented by the North Cascades Institute. Cost $95.

October 5 – 10am to noon – The Protean Coast: Exploring Seattle’s Historic Shoreline – More so than most cities, Seattle has shaped itself to suit its needs. Seattle has removed hills, filled tide flats, and created a completely new downtown shoreline. On this 1.5-mile-long walk we’ll explore the last vestiges of the former downtown bluffs, trace the island where Seattle was founded, and examine how the subterranean fill still affects the modern landscape. This program is presented by the Burke Museum. Cost is $25/general public and $20/Burke members