SR 130 begins in the west at U.S. Route 101 just east of Downtown San Jose and runs along the 4-6 lane Alum Rock Avenue. It continues over a junction with Interstate 680 through San Jose's Alum Rock neighborhood. The road narrows as it begins to run into the foothills from four to six lanes down to two. Where Alum Rock Avenue and Mount Hamilton Road meet, SR 130 heads east up into the mountains along Mount Hamilton Road, offering vistas of San Jose and the Santa Clara Valley, and traveling through some of the last remaining ranch and naturally wild land in Santa Clara County as well as Joseph D. Grant County Park. As SR 130 approaches the base of Mount Hamilton itself, the road narrows further and is barely capable of supporting two cars abreast. The narrow road begins a series of tight switchbacks that culminate on the summit of Mount Hamilton at the Lick Observatory. The observatory also serves as the existing route's eastern terminus at around 4,200 ft. (1,280 m) elevation. When snow falls on the higher elevations of the road, it is closed until crews can clear the snow and black ice. There is a small community in this area.