sentences:  The bridge was an important link in a freight-hauling route that stretched from the San Francisco Bay to Virginia City, Nevada and points beyond after the discovery of the Comstock Lode in 1859 sparked a mining boom in Nevada.Steamboats carried freight from the San Francisco Bay up the Sacramento River to Marysville, where it was loaded onto wagons for the trip across the Sierra Nevada via the Virginia Turnpike, and Henness Pass Road.The route across the bridge was ultimately eclipsed by the completion of the First Transcontinental Railroad as far as Reno in 1868 via Donner Pass, but it continued to serve nearby communities in the foothills until improved roads and bridges on other routes drew away most of the traffic.