It lies north of San Quentin State Prison.

Marin Sanitary Service is the largest tenant in the area.

[1] It opened in 1884 and was a double-track train tunnel owned by Northwestern Pacific Railroad.

[1] After a $27-million project, jointly funded by SMART and Marin County, half of the tunnel reopened on December 10, 2010, as a bicycle and pedestrian path.

[1] Sonoma–Marin Area Rail Transit uses the other half to connect the line from downtown San Rafael to the Larkspur Ferry Terminal.