A former Prairie du Chien, WI resident published a genealogy of the Maras in 1996. Those Maras came from Bohemia and lived mainly in the Prairie area.
I have some information on the Maras that lived around Eastman, WI, about 12 miles away, who were also from Bohemia. The two Mara groups aren't apparently closely related. The Eastman Maras came from the area of Jamny and Tresne, villages near Zahori and Pisek.