The public has been banned from Oxfordshire's 2,368 miles of footpaths in an effort to stop foot and mouth disease spreading.
Oxfordshire County Council is posting out signs to farmers and landowners today, giving them powers to close footpaths, and control access to their land.
Walkers who choose to flout the ban could face a fine of up to £5,000, if successfully prosecuted by the council's Trading Standards department.
Brian Yendole, assistant chief trading standards officer, said: "It will be down to the Trading Standards service to enforce any alleged infringements."
He appealed to members of the public to be "sensible" and stay away from the countryside.
Oxfordshire County Council has also made emergency plans in case the disease spreads to the county.
So far 18 farms in Oxfordshire are under investigation amid fears they might have had contact with the Northumberland farm where the outbreak began - but there are no confirmed cases.
David Orpwood, chairman of the National Farmers' Union for Oxfordshire, said the ban on animal movements, to be reviewed on Friday, was expected to be extended for a further fortnight.
He said: "A lot of us at the moment are feeling like walking off our place and leaving.
"We have gone from crisis to crisis - we haven't got two 2ps to rub together at the moment.
"On my own farm I won't be able to move animals for four weeks. I would have sold 220 pigs this week. It really affects cash flow."
He said he was unable to move 100 of his ewes, which needed to be moved because they were ready for lambing.
Rolf Denbreeje, of Danetree Veterinary Surgeons, in Faringdon, treats many of farm animals but has not seen signs of the disease yet.
"Farmers are very aware of the signs and symptoms, and we are in close contact with our clients just to make sure they know what to look for," he said.
Peter Clarke, Thames Valley Police emergency planning officer, said: "We will enforce the prevention of livestock movements, which the Government has imposed, should such action become necessary."
Jo Bird, acting chairman of the Didcot and Wallingford Group of the Ramblers Association, said the group had cancelled its planned walk at Wittenham Clumps on Saturday.
West Oxfordshire District Council has decided not to open Cogges Manor Farm Museum, in Witney, for visits.
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