For governance purposes, all of the parish south of Route 1 is part of the post-reform town of Saint Andrews,[6] the Board Road area is part of the town of the Municipal District of St. Stephen,[6] and the remainder north of Route 1 is part of the Southwest rural district,[7] all of which are members of the Southwest New Brunswick Service Commission.

[10] The Census subdivision of the same name includes the entire parish, while the former LSD of Bayside is used as a Designated place.

[1] The parish's name comes from the St. Croix River,[11] which forms part of its western border.

[17] The boundary with Saint Patrick was moved west along nearly half its length in the south.

[16][c] In 1958 the modern parish boundaries were set, losing land between the railway and the Chamcook Lakes system as well as a triangle north of Wileys Corner to Saint Andrews, gaining a triangular piece of Dumbarton Parish on the northern edge,[d] and gaining several bits of Saint Patrick by changing the eastern boundary to run entirely along grant lines and natural features.