''There have been instances where bodily harm was threatened and heaps of instances of verbal abuse. You had to develop a thick skin,'' the Doc national tenure review manager said.
Mr Perrett (66), who is Alexandra-based, is retiring after 44 years working for Doc and its predecessors.
He has spent nearly three decades working on tenure-review-related issues as part of Doc's liaison with high-country leaseholders going through the process to freehold the land they farmed.
''I've been able to get to lot of lovely places, remote places people would pay a lot of money and give their eye teeth to get to.''
He credited his work with Lands and Survey, one of the agencies rolled into Doc in 1986, as giving him the experience and skills to tackle tenure review work.
That work included roles as national park ranger in Arthurs Pass, reserve ranger on the West Coast and managing Otago's goldfield parks as chief ranger of reserves.
''My first involvement in the high country was a study exercise on the future of pastoral leases in the Rock and Pillar Range.''
When Doc was formed, he was among the few staff who knew anything about pastoral leases, so he ended up in a variety of positions which ''morphed'' into national tenure review manager after years as the tenure review manager for Otago and Southland.
In those roles, he helped develop the process which ultimately led to the Crown Pastoral Land Act 1998.
The process of negotiating tenure review, in which lessees of Crown-owned pastoral lease land agreed to surrender areas of high conservation value in return for the right to freehold, was often ''very tense, very high drama'', but he enjoyed the challenge.
''Not everyone in the high country considered Doc their best friend. You couldn't be distracted by emotions.''
As a result, there were some ''downright hostile encounters'' during the years.
''In the early tenure reviews, leaseholders wanted to freehold as much land as possible, but to get that from the Crown they had to give up something.''
Each lessee had to go over an emotional threshold before they could talk meaningfully about the process, he said.
It was a process involving major compromise by both parties, as neither party got everything they wanted very often.
One hundred and sixty-five tenure review deals had been done in the South Island, 100 of them in Otago which he or his team had been involved in.
Each review took, on average, seven to 10 years to complete.
''It's a culmination of 15 to 20 years' work to get there.''
High-country biodiversity had not been well looked after before tenure review, he said.
''When I first came to Dunedin in the '80s, there were virtually no reserves between Dunedin and Wanaka. There was nothing in Central Otago.''
In the past 20 years, that had changed, with a well-established network of conservation land on all Central Otago block mountain ranges and several conservation parks.
''These have largely been formed out of tenure review.''
Those sites protected biodiversity, historic sites, iconic landscapes and accessibility for many recreational activities, especially in Otago and Twizel, such as mountain biking, cross-country skiing, hunting and four-wheel-driving.
The contribution of the groups representing those activities helped shape the final outcome of many reviews, he said.
''They shouldn't be undervalued.''
There had also been major economic spin-offs from the process, such as 60% of Dunedin's water-supply catchment being protected as a result of the Rocklands Station tenure review.
''That had huge benefits for the population of Dunedin. The removal of cattle and the end of burning means [a] regular, reliable, clean supply of water that the city doesn't need to spend huge money on treating.''
There was also anecdotal evidence a similar process, which led to Oteake Conservation Park, was resulting in increased amounts of water coming down out of the high country due to the regeneration of previously grazed and burned tussock land which could be used for irrigation.
Now, he hoped to enjoy the ''fruits'' of his and his team's efforts by spending time out in the high country.
''I'm hoping to take my partner to some of those places I was fortunate to go, do some fishing and relaxing.''
A former Canterbury boy, he also had a soft spot for Arthurs Pass, where he spent his first years as a ranger.
''There are a lot of special memories there,'' he said.
