I just returned from a trip to southeastern Washington. The Palouse region north of the Snake River and stretching along the Idaho border was my prime destination. Among landscape photographers, the Palouse is justifiably famous for its unique landscape of rolling, wave-like fields of wheat. It is a very rich farming region, primarily known for its dryland wheat. But it’s also one of the world’s premier lentil-growing regions.
As is the case for most of our planet’s resources, where and how we take advantage of the bounty is dictated by geology and geography. This is especially true of farming. The Palouse bears a lot of resemblance to other rich farming regions in the world in at least two respects: it is relatively flat and it’s covered in a special kind of silt called loess. You can pronounce loess anyway you want. But perhaps Lois is best reserved for some women by that name. Most people in the know pronounce it somewhere between loose and lus, sort of luhs. Brits put an r in there right before the s.
Loess is a windblown silt found in many places throughout the world. It is made of angular pieces of rocks and minerals somewhat finer than sand. It forms such rich soils because the minerals in it are diverse. This is not always the case with fine debris deposited on the earth’s surface, but loess is special.
It is a gift of the Ice Ages. All over the world, when glaciers retreated (both after the last time 10,000 years ago and during previous retreats), the fine debris scoured from the various rocks that the ice passed over was left bare. Winds picked up this silt and sand and deposited it downwind, often far downwind. Natural depressions, the base of mountains, or anywhere that wind speed drops, were natural places for loess to be deposited.
In the case of the Palouse, loess from the Ringold Formation and from glacial deposits exposed to the west and south was blown in and deposited essentially in dunes. This is a big reason for the wave-like nature of the landscape. It accumulated during the drier and windier climates between glacial advances, and did so for over a million years. The loess in the Palouse reaches up to 200 feet thick in places.
Two little extra features of the loess deposits found in the Palouse help to make it such a rich dryland farming region. For one, the Cascade volcanoes to the west occasionally supplied layers of ash into the mix. This ash not only adds to the mineralogical diversity (and thus the richness of the resulting soil) but is also very good at holding water. The Palouse soils are famous for their ability to hold onto the modest amount of water they receive.
The second feature is another happy coincidence. The topmost loess deposits, blown in after the last glaciers retreated 10,000 years ago, also happen to be among the most diverse minerals-wise. So they support the richest soils. Mount Mazama in Oregon (now Crater Lake) blew its top 6700 years ago and its ash is prominently represented in these latest Palouse loess deposits.
So farmers have it good in the Palouse, growing their crops on a landscape covered in especially rich soils that hold water well. There is one little problem though: these latest loess deposits are also the most prone to loss through erosion and poor management. Just like so many agricultural areas in the world, this one requires careful management practices to conserve the precious soil.
The geologic story does not end here though. The loess deposited in long wave-like dunes originally extended far to the west of where you find it today. If you head west from the Palouse you run right out of rich dryland wheat country and into a different terrain altogether. This is the so-called channeled scablands, spectacular result of the great Missoula Floods of the last Ice Age. I will cover this great story in a coming post; suffice it to say these floods removed much of the region’s rich loess before human farmers ever got the chance to farm it.
People have been farming here since the late 1800s. In the 1880s there was a land-boom after dryland wheat farming was proved valid in the previously settled Walla Walla area to the south. In fact, the last decades of the 19th century saw far more people living here than lived in the Puget Sound region to the west. Now of course it’s the opposite. The Palouse is sparsely populated while the Puget Sound has Seattle, Microsoft and traffic nightmares. There are signs of new growth here, as some people tire of the rat race and move here, expanding the suburbs of large towns like Pullman, Washington and Moscow, Idaho into prime agricultural lands.
But for now the Palouse remains a quiet, peaceful place where open spaces are the rule. Stand atop Steptoe or Kamiak Butte and look out on the endless waves, bright green in early summer and golden brown in autumn. You’ll only see scattered farmhouses, a few barns, a few two-lane roads with little traffic. It’s a gorgeous setting, especially at sunset when the shadows are long, bringing out the unique textures and look of the place. I will surely be coming back.
Thanks for reading. Stay tuned for more on eastern Washington in the next post. Hope you enjoy the images. Please be aware they are copyrighted and not available to download for free without my permission. Please contact me if you have any questions. If interested in one of the images, just click it to get purchase options. Thanks for reading!