The LENZ Reserve was created when, in 1963, Dunedin benefactor Ivy Lenz made a bequest allowing Forest & Bird to buy 544ha of a former logging site near Papatowai, at a cost of 3200.
Thanks to the ensuing enthusiastic fundraising and volunteer construction, 50 years ago on September 20, 1969 the Tautuku Lodge was opened on site, allowing visitors to linger a little, and enjoy the reserve in earnest for the first time.
In his fundraising appeal for the lodge, then Forest & Bird Otago branch chairman Wallace Ramsay explained the reasoning behind the facility.
"The most important aspect of [the lodge's] erection is to give our young members an opportunity to learn about our Native Birds which abound in the area and to be taught appreciation of our Native flora ..."
Present day reserve management chairman Fergus Sutherland said the objective of "inspiration" remained central to the reserve's purpose, alongside its peerless research and conservation opportunities.
One such person inspired by the remote reserve and its "magical" delights is reserve management secretary Janet York, who has enjoyed a 33-year association with Lenz.
"I remember in 1987 shortly after becoming involved for the first time, two or three of us painted the inside of the main lodge. That's very much in the spirit of many who've enjoyed the facilities down the years, and helped maintain and enhance it."
Mrs York said she and her family appreciated the site's "tranquility".
"That's a common theme reading back through visitor books - people enjoying the peace, birdsong and bush walks. It has something to offer come snow or drought, and always throws up surprising new aspects and discoveries."
Excitingly, even after five decades of - albeit light-footed - human presence, the reserve continues to offer previously hidden gems.
In June, Forest & Bird confirmed the long-mooted presence of the threatened Tautuku forest gecko, following an intensive search conducted by Dunedin herpetologist Carey Knox and volunteers.
Working off a single unconfirmed sighting last winter, Mr Knox and his fellow gecko spotters have now identified at least four distinct populations of the elusive reptile, and expect to discover more during coming months.
The reserve also forms a component of the wider, 6600ha Tautuku Restoration Project, led too by Forest & Bird.
That project would study, conserve and work to restore biodiversity in the Tautuku and Fleming Rivers basin, and was now moving into a two-year "in-depth" bird survey, Mr Sutherland said.
"We've discovered native fish, geckos, and the sights and sounds of some of the reserve's rarer birds like kaka. I think what we're realising is the reserve has many more values than perhaps even the founders were aware of, when they had the far-reaching vision to establish it."
"We don't actually do any native planting, save for commemorative trees around the main facility, so the restoration takes place naturally as a consequence of significant and ongoing pest control."
Using a standardised Doc 200 trap design - many built by Otago Corrections Facility inmates - riparian and strategic trap lines are gradually being extended to control the impact of stoats, rats and, to a lesser extent, hedgehogs in the target areas.
From a starting base of just 53 traps in 2016, there are now more than 500 in place, creating protective lines totalling 35km.
A future focus would be pigs, deer and possums, all of which could be destructive to the bush itself.
Mr Sutherland extended an anniversary invitation to the wider public.
"This is really a facility for all, and we'd welcome everyone to find out more about our activities past and present."
Following a formal welcome from Forest & Bird NZ board member Ines Stager at 1pm, the afternoon would progress with expert talks, guided bush walks on the reserve's 6km of trails, and a "southern hospitality" afternoon tea at 3pm.
Between 50 and 100 people were expected to attend, Mr Sutherland said.
"This is a fantastic way to mark Forest & Bird's activities here in the South during the past 50 years. We enter the coming 50 with a lot of confidence in the future."