With security fit for a president, Cherie begins to pay off the mortgage with a £30,000 appearance

There is something of an air of mystery about the Greenbrier resort in the West Virginia mountain village of White Sulphur Springs.

There is something of an air of mystery about the Greenbrier resort in the West Virginia mountain village of White Sulphur Springs.

Perhaps it is because this upmarket spa and hotel - where more than two dozen US presidents have stayed over the years - is set back from the road, hidden from public view by trees and landscaping.

Perhaps it is the history of the hotel's now-decommissioned underground chamber, built during the Cold War to house the members of the US Congress in case of a nuclear strike, and whose existence was only revealed a dozen years ago.

Or maybe it is simply because the management refuse to permit anyone without a reservation to so much as lay foot on its well-tended 6,500 acre grounds. "I can't let you in here unless your name is on the list," declared the private security guard at the gate.

The explanation for yesterday's nervousness and super-tight security at the $800-a-night resort was the identity of the guest speaker at a conference for insurance brokers - a certain Cherie Blair, aka Cherie Booth.

While the Prime Minister prepared for a trip to Africa, his wife kicked off a three-event speaking tour of the US with an address to the 91st annual joint conference of the Council of Insurance Agents and Brokers and the Council of Insurance Company Executives.

It might not have sounded like the most intriguing group of people to have lunch with, but Mrs Blair's 40-minute speech earned her about £30,000 - a useful amount should she decide to top up her husband's health insurance policy with a little advice from the conference guests, or else put it towards the £3.6m house in Connaught Square that the Blairs are purchasing.

Of course Mrs Blair was not the conference's first choice. The actress Lauren Bacall was due to top the bill, but had to cancel several weeks ago because of filming commitments in the UK, leaving the conference organisers short of a sultry, pouting female celebrity.

"Mrs Blair is highly esteemed for her work," said Barry Meiners, a spokesman for the conference. "For women's rights, her interest in the community... she is in no way a substitute." But if the conference organisers were impressed to have bagged Mrs Blair, the residents of this small, quiet, not-quite-hillbilly town, which has for centuries been famous for the restorative qualities of its sulphur springs, were not. No one in the town, it seemed, had heard of either Cherie Booth or Cherie Blair.

"They have all sorts of people up at that place," a man nonchalantly declared at the local petrol station. "Movie stars, presidents - you name it. We never get to hear about it unless someone comes in and says they've just seen the president's motorcade." Another resident, Bobby Vance, 45, claimed he had formerly worked at the resort for 13 years, even working on the underground bunker deep beneath the hotel's West Virginia wing, known to security officials as Green Island. The bunker, built between 1959 and 1962 and equipped with 24,000-gallon water tanks and 18-bunk dormitories, covers more than 112,000sq ft, and after its existence was revealed in 1992 a local company offered bunker tours for several years.

"It was very big," said Mr Vance. "You used to get down into it by an elevator. We all knew about it, but we were always told that, if anyone asks, you say you knew nothing about it. A bunker? What's that? Nowadays, there's things going on up there that I don't think they even know about."

The Greenbrier resort speech, which was preceded yesterday by a talk from Ambassador Paul Bremer, the former top US official in Iraq, was the first of three speeches Mrs Blair is scheduled to deliver in the US. She is also due to speak at Harvard University and deliver an address to the American Bar Association.