The autumn skies were clear over California and Oregon on October 15, 2013. The Moderate Resolution Imaging Spectroradiometer (MODIS) flying aboard the Terra satellite passed over the region and captured this true color image at 19:15 UTC (12:50 p.m. Pacific Daylight Time) that same day.
Three states lie on the Pacific Coast of the United States. Only partially visible in this image, the state of Washington lies in the north. To the south lies Oregon, then California. South of California, barely captured in this image, is Mexico.
A strip of emerald green runs along the Pacific Coast, marking the well-vegetated mountains of the Coast Range. Also known as the Pacific Coast Ranges, these mountains are part of a system that extends from Alaska’s Yukon region through British Columbia, and southward through Oregon and most of California. Dark green also graces the rises of another range of mountains inland and to the east. In Oregon and northern California these are called the Cascade Range. The very rugged Sierra Nevada Mountains rise in southern California.
In Oregon, light green marks the Willamette Valley which lies between the Coast Range and Cascades. The flat, fertile valley is the most heavily populated region in Oregon. The large city of Portland can be seen as a gray smudge in the north of the valley, at the confluence of the Columbia and Willamette River. At the southern end of the valley another gray smudge marks the city of Eugene. In California, the Great Valley (or Central Valley) divides the mountain ranges. Covering about 22,500 square miles (58,000 sq. km.), this region contains most of California’s prime agricultural land.
From the west coast inland to the Cascades and Sierra Nevadas, winds drive moist air from the Pacific Ocean and precipitation is generally plentiful. On the east side of the mountains, however, the land quickly becomes dry. In Oregon, green returns on the higher Columbia Plateau and the Blue Mountains. The border of California lies just east of the Sierra Nevadas, but the state of Nevada, aside from the deep blue waters of Pyramid Lake remains very dry. The land south and east of the Sierra Nevada Mountains remains within California. Known as the Mojave Desert, this area receives an annual rainfall of just five inches.