Like generations of pig owners and turf cutters, he has treasured his free access to the steep pastures above the village of Holford. Soon, that picture of medieval tranquility may be irreversibly changed.
The National Trust, subject to a public inquiry, wants to build a two-mile fence through commoners' land it owns at Shervage Wood, along the busy A39 near Holford. The deed, supported by a powerful alliance of landowners, Somerset county council and bodies such as English Nature, plugs the last gap around the Quantocks, making the hills stock-proof.
Jim Trebble, a mild-mannered man in his sixties, says the fencing is illegal. He has written to Lord Chorley, the trust's chairman, telling him so and threatening to exercise his commoner's rights of abatement - to cut the fence if necessary. The threat, supported by members of a protest group, Residents Against the Fence (RAF) in Holford, has earned him a menacing rebuke from the trust's lawyers, Bond Pearce of Plymouth.
They warned him: 'Any wilful damage to property (of the trust) would constitute a serious criminal offence as well as other offences under the Wildlife and Countryside Act 1981.'
The fence proposal is supported by the Quantock Hills Commoners Association, the trade union of pannagers and turbarymen, but Mr Trebble is unmoved. He left the association a few years ago, feeling that it had become dominated by owners of large amounts of land who did not have commoners' rights.
'I just can't see the reason in it,' Mr Trebble said. 'If they're allowed to do this, it means I could bring 20 sheep down through the village, let them go on the road and they couldn't get up to the common. As far as I'm concerned they're taking away rights we've had since the Middle Ages.'
RAF members, including Roger Laidler, chairman of Holford parish council, believe that barriers across common land will lead to the environmental decline seen on Exmoor, where traditional beech hedges have given way to wide open spaces of sheep sward.
His view is supported by Dr Leslie Hoose, an Open University philosophy lecturer and the protest group's chief strategist. Dr Hoose, a Holford resident who has tramped the Quantock Hills for 30 years, believes there is another agenda hiding behind the conservationists' skirts - commercial pressure from landowners to fill the hillsides with flocks of European-subsidised sheep.
Dr Hoose is particularly dismayed that the crucial issue of the trust's legal right to fence common land cannot be challenged at the public inquiry, on instructions from the Department of the Environment.
The 1907 National Trust Act obliges it to keep common land unenclosed and unbuilt on 'at all times'. The DoE believes the trust is acting properly under the National Trust Act 1971, which allows it to build lavatories and car parks for tourists.
Dr Hoose said: 'The fencing is not only illegal, it will have incalculable consequences contrary to the best interests of the environment.'
The Open Spaces Society, part of the access lobby which is supporting RAF, is inviting the trust to settle the issue of the right to fence the land in a 'friendly' court action, each side paying its own costs.
A spokeswoman for the trust said the society's offer would be seriously considered. 'We'd also hoped that the public inquiry would have been a legal test case, but the DoE have decided this is not the right forum,' she said. 'We don't know why, they're not obliged to say.
'The fencing wasn't our idea in the first place. It was part of the overall management plan for the Quantocks put forward by Somerset county council. The hill above Holford can't be properly grazed because it's reverting to scrub and something had to be done. From our point of view, what we're doing is a good piece of conservation. And we'll make sure there's plenty of stiles and gates in the fence. We don't have any intention of restricting access.'
Jim Trebble remains unmoved. 'This is what the landowners want and they're out of order,' he said. 'They can't just ride roughshod over us like this. I know the trust are fairly confident they can win, but at the end of the day, they're wrong and they know it.'