Reed is an unincorporated community in Marin County, California. It is located on the Northwestern Pacific Railroad 5 miles south-southeas…Reed is an unincorporated community in Marin County, California. It is located on the Northwestern Pacific Railroad 5 miles south-southeast of downtown San Rafael, at an elevation of 52 feet. The name honors John Reed, owner of the Rancho Corte Madera del Presidio land grant on which the town is located.