The pass was named for Francisco Perez Pacheco of the Rancho Ausaymas y San Felipe. In the 1850s, an informal variant name for the pass was Robber's Pass attributed to the frequent hold-ups experienced by travelers using the route.
History
A trail nearby, through what is now Pacheco State Park, was used by the Yokuts people to cross the mountains and trade with other native people on the coast. Spanish army officer Gabriel Moraga first recorded the pass in 1805. From that time it was used by Spanish and later Mexican soldiers to cross over into the San Joaquin Valley, and for Native Americans in the 1820s and 1830s to cross westward to raid the missions and ranchos for horses and cattle. During the California Gold Rush it was used to travel between the Santa Clara Valley settlements and the goldfields and settlements in the San Joaquin Valley. However the east face of the pass was a steep and rough horse and mule trail, difficult for wheeled vehicles, until 1857 when Andrew D. Firebaugh built a wagon road with a gentler grade across the pass to what is now Bell Station, California from the Rancho San Luis Gonzaga at the foot of the Diablo Range to the east. Since then, it has been a major route between the Santa Clara Valley and the Central Valley. It was the site of Pacheco Pass Station one of the stage stations on the route of the Butterfield Overland Mail stagecoach route which connected the Saint Louis, Missouri with San Francisco from 1858 until 1861. Other stage lines used the route thereafter until completion of the railroads within the state. Pacheco Pass is registered as California Historical Landmark #829.
Nearby features
There are no major communities between Gilroy in the Santa Clara Valley and Los Banos in the Central Valley. There are no other major crossings of the Diablo range farther south until they are crossed again by California State Route 198 at an unnamed pass some to the south. The next highway crossing of the range to the north is on California State Route 130 over Mount Hamilton, approximately to the north, but this is much less heavily used than the Altamont Pass even farther north. On the west side of the pass lies Casa de Fruta, an extensive trading post in the valley of Pacheco Creek. Originally a site devoted to selling locally produced fruit and nuts to travelers, Casa de Fruta has expanded to include a delicatessen, truckstop, RV park, and other facilities. A rural locale named Bell Station also lies along the route, between Casa de Fruta and the pass. On the eastern slope of the pass lies the San Luis Reservoir, which stores water for the Central Valley Project and the California State Water Project. The San Luis Reservoir and O'Neill Forebay operate as a pumped storage hydroelectric plant. The roadway entrances to the San Luis Reservoir state recreational area and Pacheco State Park require caution entering or exiting because there are no stop signs or traffic lights and two lanes of heavy traffic in each direction. Pacheco State Park extends to the south of the pass from its entrance on Dinosaur Point Road near the pass. There is a small windfarm located at the top of the pass that can be seen from Dinosaur Point Road. The Pacheco Pass American Viticultural Area is nearby.
Pacheco Pass has been selected as the route that the California High-Speed Rail will take between the Bay Area and the Central Valley. The rail line is planned to travel under the pass in the 13-mile Pacheco Pass Tunnel, which upon completion are expected to become North America's longest rail tunnels.
