Home Postcode finder QLD Captains Mountain Captains Mountain postcode QLD Captains Mountain is a locality in Queensland covered by postcode 4357. Postcode 4357 State or territory Queensland (QLD) Region Toowoomba Region Add a free Captains Mountain business listing Be the first listing in Captains Mountain Common questionsWhat is the postcode for Captains Mountain?Captains Mountain, QLD has the postcode 4357.What state is Captains Mountain in?Captains Mountain is in Queensland (QLD).Does postcode 4357 cover more than one suburb?Yes. Postcode 4357 covers 26 localities, so the postcode alone does not identify Captains Mountain. Browse other postcodes in Queensland, or widen the search to every Australian postcode.