Note: This caption refers to the image versions labeled "NASA's Earth Observatory web site".
This astronaut photograph from the International Space Station highlights the northern California region extending from the City of San Francisco and San Francisco Bay to the west, to the cities of Stockton, Modesto, and the Sierra Nevada to the east. At night, the city lights of the major metropolitan areas reflect some of the landscape controls that determine urban growth patterns in the region. The dark waters of San Francisco Bay are outlined by the lights of the cities of San Francisco to the west, San Jose to the southeast, and Oakland to the northeast (image left).
Moving eastward from the Bay Area, the mountains of the Diablo Range present a largely dark region broken up by the lights of several smaller cities including Livermore, Walnut Creek, Concord, and Clayton (image upper left). The city lights of Stockton and Modesto mark the northern end of the San Joaquin Valley, a part of the Central Valley of California that extends for approximately 720 km (450 miles) northwest to southeast across much of the state. To the northeast of Modesto, city lights again become sparse as the mountains of the Sierra Nevada are encountered (image top right).