Until you saw it, you thought you might be the victim of some cruel local joke, an elaborate geographical snipe hunt. The San Bernardino Mountains stretch in a long arc, half encircling the city which still claims to be the nation's citrus capital even though the orange groves have long been replaced by shopping centers and housing tracts. Someone would say "It's right up there, on the hill," and you'd look where you thought they were pointing, but there were a lot of hillsides up there and you usually picked the wrong one. It got harder as smoke churned up from the Kaiser Steel Mill in Fontana and smog slipping over the L.A. county line with the Las Vegas traffic made the mountains fade and even vanish on hot summer days. Then, one day, your eyes found the right place and it appeared. A pale patch on the dark mountain, indisputably and enigmatically shaped like an arrowhead. No artifice of man was this. Geology had pushed the hills around until this shape appeared for humans to tell stories and have dreams about.