National Geographic : 1964 Jun
Booth's Amphitheater in Mammoth Cave, Kentucky, offers guide Young Hunt a convenient platform to address Boy Scouts. From this rock actor Edwin Booth delivered Hamlet's soliloquy in 1876. Part of the largest known cave system in the world, Mammoth began forming more than 100 million years ago. Early Americans prowled it in 400 B.C.; later Indians gathered its gypsum, probably for body paint and Alabama and eastern Tennessee, probably the "hottest" area in the country for important discoveries. "Most of us can only dream of going into orbit," said Bill Varnedoe, "but tomorrow any of us could be standing where no man has been before-in a new cave." Finding the Unknown Remains a Lure Every state except tiny Rhode Island pos sesses known caves. A recent poll conducted by the National Speleological Society showed 11,791 caves in the United States already lo cated and rather fully explored. Some experts believe several times as many more caves re main to be discovered. 814 Countless caves-even some developed as commercial attractions-are not fully ex plored. This fact, combined with the awe some silence and impenetrable blackness, adds to the mystery and allure of a visit un derground. I remember having to choke off a laugh upon hearing one cave visitor inquire tremulously, "How many miles of unexplored passages are there in this place?" Our American caves fall into three prin cipal categories. Drainage tubes formed by the outflowing of molten rock from active volcanoes become sinuous tunnels and blis terlike grottoes. They are the lava caves familiar in the Far West. Sea caves are sand blasted by wave action out of ocean cliffs.