Leatham Conservation Area - Marlborough's weedy wilderness.


Last Modified: 16-10-2023 17:27

Leatham River
Leatham River
Wilding conifers invade what was once a pristine environment
© Christopher Cookson  License this image

The Leatham Conservation Area is one of Marlborough’s several large wilderness areas administered by DOC, incorporating the catchment of the twin rivers, the Branch and the Leatham, bounded by the high peaks of the Raglan Range to the west, and Molesworth to the south. This is uncompromising country; Names for huts like Siberia Hut, and Misery Hut give some indication of the kind of conditions to be encountered here. Below the bush line, there’s a good deal of dense native bush, and on the river flats, plenty of prickly matagouri.

A young fella by the name of Ed was attracted to the area in the 1940s, presumably by the number of steep, high peaks over 2000 metres. His name is scrawled in pencil on the wooden frame of a hut up Boulder Stream, built in the 1930s. He later went on to climb a very big mountain in the Himalayas.

Boulder Forks Hut
Boulder Forks Hut
Historic hut visited by Sir Edmund Hillary
© Christopher Cookson  License this image

My first trip into the area was as a child, when I had the exciting adventure of having myself and my bike wound across the Leatham River in a steel cage suspended under a cable, and equipped with a pulley system. I then biked up to Greigs Hut, which in those days, was still run by the Forest Service, and had a diesel generator and electric lights. I’ve subsequently been up the Branch a couple more times, once in my late teens I think, when the most memorable thing was the family dog, Mac, catching and eating six possums along the route, and later with my own daughter, on her small bike.

I’ve been up the Leatham a couple of times as well, although somehow there was a huge gap between my last trip up the Leatham in my early twenties, to revisiting the area in my early fifties in 2023, perhaps partly due to the fact that I nearly died of meningitis about a year after my more youthful adventure, and by the time I’d regained strength to get back into the outdoors, marriage, and then a daughter intervened, but she’s now at an age that I’m regularly asked when we’re going to have our next wilderness adventure, so I figured it was time to revisit the area.

One of the advantages and disadvantages of the Leatham is access. You can get most of the way up the valley, and also up the Boulder Stream tributary in a good four wheel drive. Not having to do much walking, unfortunately encourages some petrol heads who seem to be a little deficient in brain cells. At Boulder Forks Hut, the area around the hut looked like an urban rubbish tip, with all manner of plastic and metal litter tossed over a bank. Meanwhile, at Caves Hut, someone had taken it into their head to increase ventilation in the toilet by shooting the wall full of holes.

Luckily, my 2023 trip was made during the week with a couple of ‘retired’ Anglican clergy and a medical friend of theirs, so we had no other company, and the conversation was very civilised. All three of them were amateur radio operators, so while I tend to limit my interest in the electromagnetic spectrum to the visible light part that is useful for making photos, they looked around for the longest kānuka pole they could find to rig up an antenna to talk to the outside world once twilight fell, when the conditions in the ionosphere were conducive to radio communications.

Although it was mid spring, there was still a good deal of snow about on the high peaks of the Raglan Range, and I measured the morning temperature outside the Caves Hut at -3 degrees Celsius with a compact camera I carried that included environmental sensors.

What I found most astonishing, and heartbreaking, after 28 years, was the invasion of wilding conifers, mostly pines, but also douglas firs, right up to the highest rocky ridges where little else but a few hardy alpine plants could survive.

I’d taken my mountain bike, and bike gloves, and they proved useful pulling out smaller pines, while I borrowed the saw from the hut to demolish some larger ones. I felt like I’d barely made an impact with the infested hillsides, even though I must have destroyed over a hundred pines. A few weeks later, I heard a talk at the Marlborough Biodiversity Forum that suggested my efforts might not have been in vain.

Apparently, many of the larger pines had been sown by air, back in the days of the New Zealand Forest Service, with the well intentioned, but misguided hope that they’d prevent erosion. Ironically that was the same forest service that bulldozed roads into the wilderness and established an extensive network of what are now DOC huts, that make this area so accessible.

Once mature, pines produce seeds that are wind bourne, however they take a number of years before they seed, and seeds tend not to last for long in the soil, so although the area looks like an environmental catastrophe, some determined effort could restore it to the pristine wilderness that I remember.

Although government funding to restore the area is not forthcoming, a local group, the South Marlborough Landscape Restoration Trust have raised over $1.5 million dollars towards control, although much more will be needed. It’s going to be a huge challenge to restore the area, but to paraphrase someone who frequented this wilderness before he went on to greater heights, it’s time to ‘knock the bastards off’.

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Cookson, C. (2023). Leatham Conservation Area - Marlborough's weedy wilderness.. Retrieved May, 29, 2024, from

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