Authorized visitors to the Wollemis sanctuary have to change into sterile clothing and footwear on the edge of a high cliff before descending to the site. The parks service conducts routine patrols through the Wollemi area and has set up a network of contacts with the isolated homesteads along the four- wheel drive tracks that bring visitors. Helicopter access is difficult, and television crews taken to the area have been blindfolded during the flights in and out.
Some officials take comfort from the area's natural defenses.
This is very dangerous terrain to traverse. Until six years ago, the Wollemi was thought to have been extinct for about 65 million years, or around the time the dinosaurs disappeared. Then, in 1994, a party of explorers made what was probably the first human entry on foot into one of the hundreds of canyons in the area. Noble, whose party had reached the spot by abseiling down waterfalls and swimming through subterranean natural tunnels, instantly knew that the alien form matched none of the indigenous or introduced plants he was trained to recognize. The fossils and leaves he collected were found to match imprints that had been turned into rocks 60 million-150 million years ago, long before the first people walked the Earth.