Home Postcode finder SA Dismal Swamp Dismal Swamp postcode SA Dismal Swamp is a locality in South Australia covered by postcode 5291. Postcode 5291 State or territory South Australia (SA) Region SA Outer Suburbs Add a free Dismal Swamp business listing Be the first listing in Dismal Swamp Common questionsWhat is the postcode for Dismal Swamp?Dismal Swamp, SA has the postcode 5291.What state is Dismal Swamp in?Dismal Swamp is in South Australia (SA).Does postcode 5291 cover more than one suburb?Yes. Postcode 5291 covers 34 localities, so the postcode alone does not identify Dismal Swamp. Browse other postcodes in South Australia, or widen the search to every Australian postcode.