The Columbia Basin of Eastern Washington, as viewed from space, can be likened to the hole in a doughnut, with mountains ringing a roughly circular, generally low-lying plateau. In no other part of Washington is geologic history more evident, largely because so much of it is recent. Sixteen to thirteen million years ago, during the Miocene period, outpourings of lava spread from what is now southeastern Washington and northeastern Oregon to bury the region under multiple layers of dense basalt—the most striking feature of this landscape still today. Beginning about 10 million years ago, volcanic activity shifted westward and built the arc of High Cascades volcanoes, sporadically active to the present. The uplift of the Cascades caused a change in climate as the source of moisture from the ocean very slowly was shut off, determining the Basin’s arid shrub-steppe environment. Still more recently—a mere 13,000 or so years ago—dozens of calamitous, southwestward-trending ice-age floods stripped the soils and gouged deep coulees, shaping the unique topography of bare rock and potholes now known as the Channeled Scablands.

Another transformative event has taken place within the lifetime of many readers of this book. In a triumph of engineering on a geologic scale, dams converted the Columbia and the Snake from free-flowing rivers into a series of lakes, and hundreds of thousands of acres of shrub-steppe habitat into irrigated farmlands. Today the Basin is a major producer of grains, hay, potatoes, vegetables, apples, pears, cherries, wine grapes, and hops. Irrigation runoff has raised water tables, filling many formerly dry potholes and creating extensive wetlands. A patchwork of the original shrub-steppe flora and fauna survives, although greatly reduced in extent.

The Columbia Basin is an outlier of the Great Basin ecoregion. Here one may find breeding birds typical of northern Nevada or southeastern Oregon—Greater Sage-Grouse, American White Pelican, Black-necked Stilt, American Avocet, Long-billed Curlew, Burrowing Owl, and Brewer’s, Lark, and Sagebrush Sparrows. Wetlands and pothole lakes abound with marshbirds and waterfowl. Fall offers exciting shorebirding and the prospect of a few passerine vagrants at isolated riparian groves. Winter brings many raptors to bare agricultural fields, including Gyrfalcon and Snowy Owl.

The climate of the region is dry and continental. Temperatures climb to 90 degrees and above on 30–45 days in a typical summer and not uncommonly reach the low 100s. The southern Basin is the warmest and driest part. Pasco, at an elevation of 340 feet above sea level, has a July average maximum temperature of 90 degrees and receives just eight inches of precipitation annually. By contrast, Davenport—in the northern Basin at an elevation of 2,400 feet—has a July average maximum temperature of 83 degrees and receives 15 inches of precipitation annually. The north is colder in winter (January average low temperature 14 degrees in Davenport compared to 27 in Pasco) and receives much more snow (average 40 inches in Davenport, eight in Pasco). Wind sometimes makes birding difficult in open terrain in spring, especially in the afternoons. Blowing dust can be annoying. Winter days often are marred by oppressive low clouds and fog. Drifting snow can impede travel in winter in northern areas; elsewhere the roads are occasionally glazed with ice. On the whole, however, Basin roads are well-maintained and travel is trouble-free in any season.

Lodging and services are available in Pasco, Moses Lake, Ephrata, Soap Lake, Coulee City, Electric City, Grand Coulee, Othello, Connell, Wilbur, Davenport, Odessa, and Ritzville.