Many of the immigrants that appear in the Heuser database settled from 1850 on
in the German colonies that were located in the area covered by the cities of
Santa Cruz do Sul and Venâncio Aires, in the state of Rio Grande do Sul, South of Brazil.
At this page I have collected some old maps of these colonies.
For the colonies in Santa Cruz do Sul, there are three maps:
For the colonies in Venâncio Aires, there is the
"Mapa do Município de Venâncio Aires, por Carlos Kurt Flatau" (1930).