The training area covers almost a quarter of the national park. It is rolling moorland; 58,000 acres of coarse grasses, heather and craggy outcrops stretching north to the Cheviots, home to the curlew and to rarer species such as the goshawk and the black grouse which have prospered under the Army's stewardship.
Rusting hulks of "enemy" targets are dwarfed by the natural grandeur. "In Northumberland alone, both heaven and earth are seen," wrote the historian George Trevelyan. But live-firing means that for some 300 days a year the public are barred from even the rights of way over an unsurpassed slice of the county.
The Army moved into Otterburn in 1911. It provides 120 civilian jobs, spends pounds 3.5m a year in local contracts, and helps keep alive the village shop and inn. It wants to upgrade the training area so that the artillery can hone its "shoot and scoot" tactics without sinking into the peaty moorland.
The national park accepts the presence of the military and the need to adapt for modern warfare. It was ready to say "Yes" to the wider roads, extensive maintenance facilities, and observation points, but has balked at six of the proposed 46 gun spurs - the hard-surfaced areas from where the guns are fired.
"Our objections are based on the environmental impact," said a park spokesperson. "It's visual, it's noise, it's the incongruity of some of the activities. We have moved an enormous distance. But the Army have not moved one inch on the scale of the development."
The Army points to 53 "mitigating and balancing measures", such as no live firing on August weekends and safeguards for ancient monuments, but remains adamant that the ability of AS90 and rocket- launcher crews to practise deployment procedures over 46 gun spurs cannot be compromised.
As Northumberland County Council have refused planning permission, the matter is in the hands of the Secretary of State for the Environment, John Gummer. The Army has assembled a legal team in expectation of a public inquiry and is talking of costs of pounds 2.5m - twice the annual budget of the park.
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