No single issue arising out o f the Mining Law has provoked more discussion than that o f what constitutes a discovery o f valuable mineral deposits. The concept o f discovery has been described as the sine qua non for establishing the validity of a mining claim,1 and the most crucial element in protecting claims against incursion by others-in short, the linchpin o f the Mining Law.2 Judge Lindley put it this way: cc[I]n the mining law o f all civilized countries the great consideration for granting mines to individuals is discovery” 3. For when a valuable mineral deposit has been discovered the claim­ ant gains a property interest protected against all others, including, especially, the federal government.