Goden Gate Transit Buses 40 and 42 travel from several locations in Richmond to the San Rafael Transit Center. from there there are seveal buses that travel south to Crte Madera and beyond. To plan your trip, call 511-455-2000 (toll-free) or 415-(outside the Bay Area).
You would have to take Golden Gate transit routes 40/42 which runs through Richmond to the San Rafel transit center and transfer buses . Route 40 is an express version of route 42 and operates peak weekday periods only. Then you would have to transfer to a Marin Transit Bus #22 to Corte Madera.