It is an old European custom for a village to proclaim its faith by erecting a cross in a prominent place, and the Alsatians brought the tradition with them when they came to the Medina Valley.  The obvious place for Castroville's cross was the hill name Mont Gentilz.

Theodore Gentilz was a friend of Henri Castro who served as the surveyor of the colony.  It was he who laid out the towns of D'Hanis and Quihi as well as Castroville, plus outlying farms.  He moved to San Antonio after his work was done, and became a well-known painter of early Texas scenes.

The first cross was erected about 1850, just a few years after the town was settled.  It was consecrated by Father Claude Dubuis, first pastor of the parish.

Another cross was erected in 1902; the record is not clear whether this was the second or third cross on the site.  A Corpus of zinc was attached to the cross, so that it became a complete Crucifix.  It overlooked the valley for about 20 years until vandals tore it down and threw the statue into the canal behind the hill.

The next cross to grace the hill was of wood from two telephone poles donated by a parishioner.  It was dedicated on Good Friday of 1929 or 1930, and it lasted for 40 years.  It was replaced in 1971 by the present concrete cross, 13 feet high and 7 feet wide, that was cast in Piedras Negras, Mexico.  The spirit of ecumenism is strong in Castroville; the dedication service of the new cross was conducted by the congregations of St. Louis Catholic Church, Zion Lutheran Church and Castroville Baptist Church.

It used to be the custom for the St. Louis congregation to walk to the summit on Rogation Days to pray for the blessing of their crops, and to petition for rain in times of drought.  The children of St. Louis school had Lenten services at the cross.  These traditions have faded now, but the Cross on Mont Gentilz still casts its protective shadow over Castroville.