He and his team spent hours, often in cold, muddy conditions, digging out a hole for what is now the Rainbow Pool.
They also planted hundreds of trees and ferns, before opening the park to the public in December 1932.
Park warden Ray Punter started working at Rainbow Springs 45 years ago, shortly after arriving to New Zealand from Africa.
"We once had pheasants, doves, deer and pigs. At different times we also had donkeys, stoats and Pacific rats called kiore. Now Rainbow Springs offers more entertainment – we have the Big Splash ride, children's playground and new play installations."
Punter said he stayed at Rainbow Springs for so long because he loved being outside.
"I'm outdoors in the fresh air, in amongst the trees and ferns, trout pools and birds. It doesn't matter if the sun is shining, it's blowing a gale or it's raining, as long as I'm outside I'm happier."
Rainbow Springs business manager David Hennigan said it was wonderful what the park had achieved over the last 85 years.
"We're using this occasion to look to the future.
"We recently added six unique playscapes to the experience including a waterplay area and we will soon be upgrading some of our buildings, introducing more encounters and guided excursions and doing a refresh of some of our core experiences such as the Kiwi Encounter and the Big Splash."
Also this month Rainbow Springs is welcoming kōkopu (giant kōkopu) to the park. Kōkopu are a declining species of endemic Galaxiidae fish which grow to 45cm in length.
It's also opening a new whio encounter later this month, where visitors will be
introduced to the rare blue ducks recently moved into the park as part of a breeding programme.
To celebrate the milestone Rainbow Springs is giving anyone over 85 free entry into the park for the whole of March and has reduced the cost of an annual family pass to $85 (cheaper than a family day pass).
Both offers are running until March 31and can be obtained at Rainbow Springs, or at rainbowsprings.co.nz using the promo code '85years'.
