Washington State and the Pacific Northwest are often known for Western Washington’s tall evergreen forests, rainy coastal beaches, mossy rainforests, and snow-capped mountain peaks. But if you cross east over the Cascade Mountains, you’ll find a totally different landscape: a drier climate, wide open prairies, the distinct rolling hills of the Palouse region.
The region is so named due to its original inhabitants: the Palouse (or Palus) people, a Sahaptin-speaking group of nomadic people indigenous to the area. During the period of indigenous land stewardship, the Palouse region was a grassland dominated by bunchgrasses, wildflowers, and shrubs. The 1861 map below, created less than a decade after the area was organized as part of Washington Territory in 1853, broadly describes this area as the “Great Plains of the Columbia.”
The 1862 map below begins to show the detailed signs of American westward colonization of the region: extending across the northern section of the map, you’ll see “Captain Mullan’s Wagon Road,” the first wagon-supporting road built to cross the Rocky Mountains in 1860. The road was built by the US Army and ran between Walla Walla and Fort Benton, Montana, eventually used by western gold-seekers. Also visible are reservation boundaries for the Nez Perce people (another group indigenous to the area). Just seven years prior to this map’s creation, the Walla Walla Treaty Council instituted reservations for both the Nez Perce and Yakama peoples following the Cayuse War.
Only a small section of the map (near Walla Walla) is sectioned out into township and range survey grids. Over the next decade, agriculture would take off in the area, as American settlers realized that dryland farming, or relying on natural rainfall without irrigation, was well-supported by the region’s fertile soils.
What characterizes the region’s unique topography is loess soil, which created by fine-textured, wind-blown silt that stacked up over time into very thick layers. The deep loess soil sits over basalt rock and retains moisture well. In the photo below, taken by Carol Highsmith near Palouse Falls State Park, you can see exposed columns of basalt rock along the river bank, which undergirds much of the Palouse region.
The Columbia River Basalt Group was created by volcanic eruptions that flooded basaltic lava over large areas. In the Palouse, these basalt formations were then covered by loess soil, the source of which was likely silt generated by glacial outwash, picked up by the winds, and left on the the top of the deep basalt flows. In the Palouse region, loess soil deposits can go down hundreds of feet deep. The 1902 map below, produced by the United States Department of Agriculture’s Bureau of Soils, shows soil composition near Walla Walla, Washington.
The Palouse quickly became a wheat-growing hub, with winter wheat production hugely successful without irrigation. However, the hillside topography required complex techniques to use machines on the hillside slopes. The 1890 map of Whitman County (below) proclaims the county’s achievement as “the greatest wheat-producing county in the State of Washington.” It was in 1890 that the Washington Agricultural College was founded in Whitman County. Today the college is known as Washington State University. Throughout the late 19th and early 20th century, researchers based at the school experimented with agricultural techniques that helped drive agricultural production in the area.
The region’s incredible soil wasn’t just productive for farming: it’s also the home to great earthworms. The Giant Palouse Earthworm was first described in the late 19th century and said to be transparent with a pink head, extend up to three feet long, and smell like lilies. After mechanized plowing took over the fields, the sightings dropped off, but reports continue to emerge over the years, with the legendary worms thought to be living very deep down in the soil. In 2010, The New York Times ran an article titled “Found Alive: The Loch Ness Monster of the Northwest Prairie, Alas It Disappoints” (E). In the article, author Jim Robbins describes the discovery of two Giant Palouse Earthworms by a University of Idaho graduate student. In a devastating turn of events, the earthworms were at most 9-10 inches long and did not smell like lilies. Once thought to be extinct, sightings of the Giant Palouse Earthworm continue, as documented by the Palouse Prairie Foundation (E), which also provides a delightful photo of said earthworms.
Today, the Palouse’s picturesque rolling hills remain covered with wheat, as the area continues to be a major producer of wheat for the United States. This is documented in the map above, produced by the United State Department of Agriculture. Interest remains in localized attempts to restore the area’s native grasslands, with government efforts such as the Natural Resources Conversation Service’s Native Palouse Prairie Restoration and the aforementioned Palouse Prairie Foundation (E).
