Mr Young, who died in April, would have celebrated his 90th birthday last Sunday. .
On Friday, his daughters, Rachel and Penelope Young, marked the occasion by helping unveil a sign which formally recognises a reserve beside the property as the Ivan Young Zoological Reserve.
Rachel Young said her father, an animal lover, was parks and reserves curator for the Queenstown Borough Council for 14 years from 1962.
He began rescuing animals and the collection he assembled on what was a former council dump quickly grew to include horses, wallabies, ferrets and a variety of birds.
When a fire in the late 1960s destroyed the birdcages, Mr Young rebuilt them. At that time he also registered the 3ha property as a zoo.
''His whole life he just loved animals - my grandmother said she used to hate making his bed when he was a child because she never knew what was in it,'' Ms Young said.
''On his trike he had a rooster as his pillion passenger. He built his own pond for fish and aviaries for birds.
''He built his dream from nothing - it was a dream for him and we're carrying on that dream because that's all we know.''
The gardens now contain a wide variety of birds, including peacocks and pheasants, cats, horses, pigs and chickens, while visitors can also feed trout in the Kawarau River, which borders the property.
Most of the animals had been abandoned or were strays and were taken in by the family. However, the Youngs will not accept animals simply because their owners no longer want them.
Ms Young said the reserve, which includes a playground, was leased from the council.
Her father had transformed it from a dump, but it was never named.
Queenstown Lakes Mayor Vanessa van Uden said she was ''honoured'' to be asked to unveil the sign, which was provided by the council.
''Ivan worked for council for a long period of time, then took those skills and his knowledge to turn what was a dump into what we have here today.
''As a community we're really very fortunate as we wander into the reserve that you look after it for us,'' Ms van Uden said.
''It's an oasis right next to one of the busiest shopping areas in town.
''To have somebody in the community who was prepared to take in the waifs and the strays ... not just the animals ... there aren't very many people like that.
''I am in awe of you two carrying on his vision,'' Ms van Uden told the Young sisters.