The Cal Park Hill Tunnel runs for 1,106 feet through the hill to Larkspur. It opened in 1884 and was a double-track train tunnel owned by Northwestern Pacific Railroad. Train service stopped in the 1960s. It is now owned by Sonoma-Marin Area Rail Transit (SMART). After a $27 million project, jointly funded by SMART and Marin County, half of the tunnel reopened in December 10, 2010 as a bicycle and pedestrian path. Sonoma-Marin Area Rail Transit plans to use the other half to extend their planned commuter rail line from downtown San Rafael to the Larkspur ferry terminal.