Via BART: All BART lines except Fremont (Orange Line) stop at downtown San Francisco. If you are on the Fremont (Orange Line), find the closest station that has one of the BART lines leading to downtown San Francisco. Once you’re on BART, proceed to stop at Powell Station. Any of the escalators lead up to Market Street. Continue onto Market Street towards Stockton Street and take the 1st right onto 4th Street. Mosser Hotel will be on the right side on 4th street.