Stockton Street Tunnel

Wikipedia records that a petition for the tunnel was filed on 23 January 1909. It was cut to ease the climb: the grade north from Sutter Street had been 18 percent and the grade south from Sacramento Street 12 percent, while the tunnel holds a maximum of 4.29 percent between Sacramento and Sutter. Stockton Street was lowered at the southern approach, which shows at 417 Stockton Street, where the basement became the ground floor and the old front door is a marked window bay on the second floor.