But there was no way of avoiding something less than beautiful on the road down to the river - a clutch of houses in a clearing, solidly enough built out of stone and timber, but surrounded by dented pick-up trucks.

To complete the scene of desolation, there were no washing lines, no children's toys outside the front door, not even a dog. But the strangest thing was the cabin in the middle - it had been blown apart in what must have been a huge explosion.

The place stank of charred wood and broken drains - with a fugitive chemical reek that pricked the eyes and throat. No human form stirred in the houses - not that you could see.

"Meth," said my old London friend, now a proud Oregonian housewife. "Crystal meth did this."

"What do you mean?" I asked her naively. "What happened?"

"The guy in that house - he was cooking meth. Had a lab in the kitchen. It blew up. We knew him a bit. He burned to death."

A drug-free zone? Some hope in this rugged corner of the U.S., which, per head of population, has more makers and users of the illegal drug than any other state.

Crystal meth underpins a sub-culture of reckless hedonism that came out of biker gangs and gay clubs in the Nineties and clambered up the mountain trails. The "guy in the house" was called Peter, I discovered later. Once he had had a job and family, but then he became hooked on crystal meth and decided he liked it more than anything else.

It gets people like that. Peter hid away in his cabin, in between making furtive trips to his local supermarket to buy Sudafed - a common cold remedy that contains crystal meth's key 'precursor chemical' pseudoephedrine.

To complete his concoction, he added some drain-cleaner, a pinch of lithium from a battery, iodine and phosphorus from some matches and began cooking the ingredients in the middle of the night. Then his stove-top laboratory exploded. He was 51.

The are various recipes for crystal meth - a few clicks of a computer mouse will find them on the internet. But these are for beginners - in Oregon, as in all over the U.S., the knowledge of how to make the drug is already out there.

The U.S. authorities tried to make life difficult for the home-brewers by restricting the sale of cold remedies. But addicts just went from shop to shop to buy two-packet allowances of Sudafed and Tylenol Flu Strength - a practice known as 'Smurfing'.

When that trick was rumbled, organised crime moved in. Investigations concluded last year that 80 per cent of the methamphetamine consumed by an estimated 1.4 million American addicts is made by criminal gangs in Mexico.

Coming in powder or crystal 'rocks', it can be snorted, smoked, eaten or melted and injected. It dumps the brain's supply of the natural hormone dopamine into the bloodstream in one euphoria-inducing blast - supposed to evaporate sexual reticence and give the user a sense of omnipotence.

It ages the skin and rots the gums. Collapsed faces framing toothless mouths have been the subject of shock before-and-after 'meth makeover' poster campaigns both in the U.S. and in Britain.

The Association of Chief Police Officers heard at its conference about the damage the drug does to families and communities as every bond of human relationship is corroded.

The drug's assault on white, blue-collar, small-town America is what has made the loudest media noise. Those hopeful drug-free signs sprout not just on remote mountain trails but around shopping malls and high schools. It is not the children who are the problem - but so-called 'Meth Moms'.

Women use crystal meth at the same rate as men. Some start because they think it will help them lose weight. The narcotic seems to get its initial grip as a way for bored housewives to get through the day. Until taking crystal meth becomes their day.

The British police chiefs also heard about the dangers of dealing with socalled 'tweakers' - crystal meth users gripped by paranoia and violent urges at the end of a week-long sleepless cycle of 'speeding'.

When, last November, President George W. Bush declared America's first Meth Awareness Day, he said: "Methamphetamine is a powerfully addictive drug that dramatically affects users' minds and bodies. Abusers can transform homes into places of danger and despair."

They certainly can. A recent U.S. investigation concluded: "When parents crash after days of speeding on meth, their children are left to fend for themselves, sometimes for days.

"Parents under the influence of meth may also sexually or physically abuse their children."

Those words concealed multiple horror stories of children left in filth - of 'meth orphans' taken into care as their hollow-eyed parents were led stumbling towards court and prison.

First it was in California, then Oregon. Now crystal meth has reached the Mid-West and is rapidly heading south and east as production becomes industrialised, selling becomes more ruthless and demand, especially among high school teenagers, increases.

Twelve million Americans are said to have dabbled with it. The backwoods hobbyists have been overtaken - but that is how, like some alien invader, crystal meth first takes hold.

And that is what so alarms police authorities here. At their special drugs summit, the Association of Chief Police Officers warned that crystal meth was on its way to outstripping crack cocaine as the nation's most dangerous and prevalent drug.

According to Commander Simon Bray: "It could become as popular as crack unless we recognise the potential danger it poses and take action to prevent its spread.

"There is increasing intelligence about methamphetamine which shows its presence in this country is growing. You can find it in Hampshire, Lincolnshire, Derbyshire, London - if people want to get hold of the drug they can find it."

Detective Chief Inspector Jason Ashwood, a senior member of the ACPO methamphetamine working group, told me: "It's been in the gay club scene for some time, but intelligence and street finds show it's crossing over to the mainstream drug user - homeless men, rough sleepers, crack and heroin addicts."

Mr Ashwood, who is based in South London, has no doubts as to the seriousness of the threat. The small number of busts and convictions so far hardly conveys the effects the drug is having on the streets and the potential for wider mayhem as addicts turn to crime to buy the drug from organised criminal gangs fighting for control of its trade.

"What it does is devastating," Mr Ashwood said, explaining that the vital difference between crystal meth and other drugs is that it can be manufactured at home.

But unlike in America, there are no moves yet to increase restrictions on the sale of over-the-counter cold medicines in this country, although bulk transfers from pharmaceutical plants in China and India are monitored by intelligence agencies.

It was the warnings from across the Atlantic that caused Home Secretary John Reid to begin moves in Parliament to combat methamphetamine. The latest reclassification means police now have the legislative tools and the motivation to shut labs down.

Their primary targets are criminals making the drug to sell rather than amateurs brewing it up for "domestic" use. Both are highly dangerous - and not just to crystal meth users.

The Manchester conference heard from U.S. officials about the hazards of cleaning up toxic and explosive crystal meth kitchens.

One state, North Carolina, legally equates the making of methamphetamine with possessing weapons of mass destruction. Meanwhile, the U.S. Drug Enforcement Agency (DEA) is now obliged to post public details of laboratory discoveries, so dangerous are the residues.

In contrast, there is just one special clean-up team in Britain, while a member of the DEA, working from the U.S. embassy in London's Grosvenor Square, is providing British officials with expert advice.

A monster is stalking us. But the warning has been posted. Crystal meth is deadly, it is in this country and more is coming.

The Daily Mail