After over 100 years of campaigning for more access to our open spaces, today marks the first chance for walkers to explore pastures new. Mark Reid, The Northern Echo's walks correspondent, explains what the new Open Access rules will mean.

Since the Parliamentary Enclosure Acts of the early 19th century literally fenced off our countryside, huge swathes of upland Britain have been out of bounds for the outward bound.

True, the Rights of Way network provided many thousands of miles of footpaths and bridleways from which to enjoy our countryside, but there were still mountains, hills and open tracts of moorland closed to walkers with the threat of trespass if we dared make it to the summit. This will all change today.

After over 100 years of campaigning for improved access to our hills and open spaces, the Countryside and Rights of Way Act (CRoW) 2000 will come into force throughout the North of England.

This historic day will see hundreds of square miles of mountain, moor, heath, down and common land throughout the Yorkshire Dales, North York Moors, Lake District, North Pennines and Northumberland opened up so that walkers will be able to walk freely across open ground without having to stay on footpaths. In the Yorkshire Dales National Park alone, the amount of Open Access land will increase overnight from around four per cent currently to an amazing 62 per cent - that's an extra 400 square miles. By the end of 2005, 4,000 square miles of England will have been classified as Open Access land.

There are concerns. Some landowners are worried that roaming walkers may damage fragile heather moorlands, highly prized for grouse shooting, and walkers' dogs may cause havoc during the bird nesting season.

Several people have said to me over the past year or so that they believe these new rights of access have gone too far. "How would you like people wandering through your back garden?", they say. Let's get this straight. These new rights of access relate to mountains, hills and areas of open moorland NOT back gardens, parks and houses, or enclosed fields for that matter.

The areas of Open Access have been researched, scrutinised and mapped out over the last five years and will feature on all new editions of Ordnance Survey Explorer maps as pale yellow shading.

This new found freedom brings with it some important responsibilities. The fells, hills and moors of Northern England are almost all privately owned and provide farmers and landowners with their livelihoods. Upland areas are home to sheep, cattle, grouse and many important ground-nesting birds.

We all have a duty to respect and protect the countryside. These new rights of access cover most recreational activities carried out on foot such as walking, bird-watching, climbing and running. Open Access does not cover cycling, horse riding, driving a vehicle or camping, but where rights already existed (such as a bridleway) then these remain unaffected.

Some areas are always out of bounds even if they lie within Open Access land, such as buildings, houses, gardens and quarries, and you may not light fires, feed animals, leave litter or do any damage.

Dogs are generally welcome but must be kept on a short lead during the spring breeding season or at any other time of year when near livestock; dogs may also be subject to specific restrictions (such as exclusion from grouse moors), so look out for local signs. By law, a farmer may shoot a dog that is attacking or threatening livestock. In summary, the new rights of access are for responsible walkers, subject to some common sense restrictions.

Most walkers want to get from A to B with the least difficulty; very few will just wander aimlessly across open heather moorland. A recent survey of Barden Moor and Fell in the southern Yorkshire Dales, an area that has enjoyed open access for a number of years, showed that the vast majority of walkers remained on recognised tracks and paths. If you have ever tried walking through thick heather then you will understand why.

In reality, this new Open Access will allow people to visit viewpoints or landmarks off existing paths, head along ridges linking inter-valley Rights of Way or tackle summits of previously 'closed' hills. These are known as 'desire lines' and in due course will get their own footpaths as people follow the obvious routes or stick to existing estate tracks that trace across the grouse moors. Many authorities have anticipated these 'desire lines' as well as the key access points and have already started to put up new gates, stiles and information boards.

Jon Avison, Yorkshire Dales National Park Authority Head of Park Management, explains: "Open Access gives people a chance to see areas of the Yorkshire Dales National Park that were inaccessible before. It will help us achieve one of our main purposes - to give people the opportunity to enjoy the special qualities of the National Park. But people do need to remember that the new right does not allow them to walk wherever they want."

"It will have an impact on farmers and landowners in terms of the management of their activities but there are measures in the Act that allow them to restrict access to certain areas at certain sensitive times of the year such as the lambing and bird breeding seasons.

"People will certainly explore new places but we think that the impact of this will be limited, bearing in mind that there are more than 2,000 miles of well-used public rights of way across the National Park already. One of our key jobs for the next year will be to monitor the impact and to make sure that people understand their responsibilities, follow the Countryside Code and take note of any signs that they see in the countryside."

Open Access will allow people to experience a whole new world of views, landscapes, interest and challenges. It will provide an opportunity to find those special places that have previously only been seen by a handful of people, places where nature is close at hand.

Mark Reid is author of The Inn Way series of walks books

www.innway.co.uk