'About Caves and Other Secret Hiding Places in the World', by George Wagner Jr, published in the January 1967 issue of Search. In discussing the various reports he had collected about the mysterious place, Mr Wagner mentions some specific details `written to me recently by one of my correspondents, Mr. Azerland':
He stated that about 75 miles northwest of Portland, Oregon, between Portland and the Seattle earth-faults, far down in the earth, where the earth was once flooded over, are the remains of a splendid city. My correspondent says that the city is about eight to ten miles underground, and is reached by a number of tunnels which radiate from it in different directions.
Mr Wagner's article gives the impression that he believes the underground city to be of Atlantean origins (citing the reference to flooding) and perhaps similar to other subterranean dwellings reported in South America and Asia. This would certainly strengthen the argument for it being part of the great world-network.
Continuing still further north, into Alaska and the region of the Bering Strait, we can find more evidence of a subterranean tunnel. Among the people here, and in particular the ethnic race of Indians, the Athapascans, there is a belief in a subterranean race who have lived in harmony and secrecy since before the arrival of the Indians themselves. In his fascinating book, Arctic Adventure - My life in the Frozen North (1935), the intrepid adventurer Peter Freuchen makes a number of references to stories he heard among the Indians about the Eqidleet, or Inland People, who live below the surface. In the heart of Alaska, not far from the town of Tanana, he was shown crevices in the mountains where, he was told by his guide Asayuk, men had disappeared over the years to go and join the Eqidleet. Freuchen writes:
The crevices were deep and broad, but Asayuk found a way in and out between them, seemed to know instinctively where they were, and took us safely to the land we sought. Asayuk told me of desperate men who had run away from home and gone into the mountains to get away from their fellow men. They had become ghosts or were taken in by the Eqidleet.
The Eskimos who dwell in the far north of the continent also have a number of legends concerning a race of people living beneath the earth's crust. These underground people have a system of tunnels through which they can travel to and from the surface world. According to William F. Warren in his book, Paradise Found, or The Cradle of the Human Race (1911), the Eskimos believe that their ancestors may well have come from this subterranean world which is lit by a perpetual light. They almost certainly knew of the whereabouts of the passageways, though these are now probably forgotten.
Fascinating though all these reports are, the most important evidence and conclusions have come from the south of the United States, in Arizona to be precise, where a dedicated researcher named Charles A. Marcoux has spent the last quarter of a century investigating the legends of a subterranean world. To formalize his work, Marcoux has established the Subsurface Research Center in Phoenix, Arizona, having picked this particular locality because he is convinced an entrance to the subterranean tunnels exists in a curiously named local mountain range known as the Superstitious Mountains.
Marcoux has made an intensive study of all the accounts of underground passageways throughout the world, and is already convinced that `a network of tunnels exists from Canada to South America, especially under Brazil, all of which are connected by tunnels with other parts of the world'. However, the tunnel network which particularly interests him is `the one that opens at various points in Central and South America, with an entrance in the Superstitious Mountains in Arizona'.