The long march from Kinder Scout: map sets out rights of way in a shrinking countryside

It is more than seven decades since a few hundred working men from the factories of Manchester and Sheffield laced up their stout shoes, packed their sandwiches and did battle with the Duke of Devonshire's gamekeepers.

The 1932 mass trespass on Kinder Scout mountain plateau in Derbyshire was the first historic step on the long march for freedom of access to countryside which, privately owned, had been the sole preserve of aristocratic shooting parties and their game birds.

Tomorrow, that 70-year journey reaches its final staging post.

A conclusive map of southern England published under the Countryside and Rights of Way Act (2000) means that, for the first time, millions of ramblers can see exactly where they will have the long cherished right to roam. The public will earn the right to use the new map later this year, on 19 September.

Launched by the government's Countryside Agency, the map covers just under 50 sq miles of open countryside in Kent, Sussex and Surrey, some of the most beautiful landscape in England, including precious chalk downland under threat from agriculture. The new access boundaries can be viewed on the CA website from tomorrow.

There is already a 140,000 mile network of public rights of way in Britain, but this goes further and marks large areas of privately owned land now judged suitable for walkers.

It is a remarkable achievement for groups such as the Ramblers' Association and the Open Spaces Society, which have fought stiff opposition from country landowners and farmers, some of whom see walkers as unwelcome and sometimes dangerous intruders despite their contribution to the economy.

They have battled so hard, and the new laws have worked so smoothly, that the first officially approved steps under the CROW are scheduled for several months earlier than had been first anticipated.

The Ramblers' Association is planning to mark the date with a series of celebratory hikes on the new open land, one of which, it is hoped, will be attended by the Minister of State for Rural Affairs, Alun Michael.

The next area to be formally opened up will be the "lower North West", and the final maps for this are eagerly anticipated. It includes Kinder Scout itself, as well as the Duke of Westminster's vast Bowland estate in Lancashire, long a target for walkers.

Kate Ashbrook, the chairman of the Ramblers' Association's access committee and general secretary of the Open Spaces Society said: "The map is a milestone, and shows that access is finally on the way. For the first time we'll be able to see where we can enjoy our new freedoms.

"We're delighted, too, that we can start enjoying the countryside on 19 September. We just hope that everything progresses as smoothly for the other regions. A lot depends on the number of appeals from landowners."

The only downside of the first map, she said, was that it made clear just how much ancient chalk landscape had already been lost to the plough.

The Countryside Agency is still working its way through the other regions of Britain, but they will all be completed by 2005, by which time a total of 4,000 sq miles will officially become open to the public.

Inspectors are judging appeals from landowners who believe that their properties have wrongly been included on the draft maps.

Pamela Warhurst, the CA's chairwoman, said surprisingly few landowners had contested the status of uncultivated land to be used by the public.

"Aside from one or two celebrated cases, the vast majority of landowners have worked constructively to get this legislation right and, ultimately, people have accepted this as the law of the land," she said.

Chris Smith, the former culture secretary and the new Ramblers president, said the map marked a historic milestone, and came at a time when physical exercise was of paramount importance for the health of the nation.

"If I had to pick one issue out, it is the importance of walking as part of a healthy lifestyle. We're gradually waking up now to the problems of obesity and the need for people of all ages to be active. Walking is absolutely the best way of keeping fit," he said.

He was also concerned about the plight of urban walkers, who find themselves squeezed out by the car, and the minority of recalcitrant landowners who block traditional rights of way.

Governments, he said, had tended to focus on diet as the main cause of obesity, but sedentary lifestyles were also to blame and now needed official attention.