Camping and woodcraft - Scoutmastercg.com

338 CAMPING AND WOODCRAFTare sealed or masked from our observation, and yethave left marks by which their existence can beproved.Cave "Sign."—The surface indications of acavernous region are easy to read. Take the OzarkPlateau, for example. Anyone traveling crosscountryfrom the Missouri River toward Arkansaswill notice that the surface rock mostly is limestoneand that it is commonly porous or fissured,being easily ''eaten" by the elements. Often hewill observe what geologists call vermicular limestone,full of little holes like those that earthwormsbore in the soil, or like what "sawyers" bore inpine timber. He will cross some fine rivers, generallyvery clear, but will marvel at the almost totalabsence of brooks and spring branches; this evenin a country that is distinctly mountainous.In summer one may travel sometimes for a dayin the Ozarks without finding running water. Hemay come to the perfectly dry bed of a water-coursethat evidently drains a considerable territory, andhis driver will tell him that this "dry fork" carriessurface water only for a short time after aheavy rainfall. The real drainage stream flowsunderground.When a spring is met in this region it islikely to be a large one. A typical "big spring"boils out of a hillside and fills a crater-like basinsixty to a hundred feet in diameter. Its surfaceis blue as indigo. The water is so clear that, byimmersing your face, you can see the white bottomforty or fifty feet below. The outlet is strongenough to turn a mill, and forms at once a creeknavigable by canoes. Such are the St. James Springon the Meramec, the Round or Blue Spring on theCurrent River, Bryce's Spring on the Niangua, andMammoth Spring near the Missouri-Arkansas line.On wide plateaus, where the drainage is notabrupt, our traveler will see numerous funnelshapeddepressions In the fields, into which sur-