AS ITS replica chugged away on Kent St on Sunday morning, direct descendants of the engineers and owners behind Queensland's first steam engine celebrated exactly 140 years since the train was unveiled to the public.
A crowd of about 50 people was on hand as two kauri pines were planted in Maryborough's Federal car park to honour the two men behind the building of the Mary Ann.
Built by John Walker and Co, the steam engine was commissioned by William Pettigrew and William Sim to haul kauri pines out of the Cooloola Coast forest.
Its replica, built by Olds and Sons in 1999, can now be seen showing the sights of Maryborough to visitors.
Peter Olds led the ceremony with Fraser Coast Mayor Gerard O'Connell.
Mr Olds said the Mary Ann was named for the daughters of Mr Pettigrew and Mr Sims, who were both called Mary Ann.
Direct descendants of both men were on hand to help plant the commemorative trees.
Merril Patrick travelled with her family to Maryborough especially for the occasion.
Her great-great-grandfather Robert Black was the engineer who worked on the Mary Ann and her father and sister are drivers on the replica. Merril's grandson Bailey was the youngest descendant at the ceremony.