Sacramento, the capital of California and the western terminus of the Pony Express in the late 1850s and early 1860s, is visible in this near-vertical photograph. The city, an important transportation center for the truck farms of the rich Sacramento Valley, lies 72 miles (116 kilometers) northeast of San Francisco. Sacramento is a deepwater port via a channel that leads to Suisun Bay. Agricultural field patterns are visible on either side of the Sacramento River, the longest river in California. The American River, flowing westward from the Sierra Nevada Range through Folsum Lake, joins the Sacramento River. Major transportation arteries appear as straight white lines north of the city heading east into the foothills of the Sierra Nevadas.