Mystery Mountain — Florence Laughlin

Almost seventy years ago, on a solitary foray into the wild mountain region beyond his ranch, the first Daniel Glover disappeared among the rugged, storm-swept crags of Mystery Mountain, and with him the secret of the gold mine he alone had discovered. To his great-grandchildren, spending the summers with their Aunt Charlotte in the old adobe ranch house at the mountain's foot, no project in the wonderful Arizona country--not even the riding of the spirited horse Flecha--presents such an irresistible challenge as the use of their ancestor's unfinished treasure map to find the family's lost heritage. And this, young Dan Glover's fourteenth year, is to be the grand occasion for a full-scale pack-toting, horseback-riding camping trip into the mountain wilderness with Aunt Charlotte's foreman, Gordon Halliday, to search for the lost Phantom Pony Mine.

But on the eve of the departure a young stranger who looks like Dan's twin arrives from New England, bearing a treasure map that is almost the duplicate of Dan's own and a bona fide claim to the hidden fortune Dan seeks!

When Dan faces the rivalry of this new and irritatingly learned boy from Boston, the feminine wiles of his strong-willed sister, Karen, and the conflict with his own sense of confidence and self-esteem, it is only the beginning of a grand adventure in which generosity and kindness turn out to be just as important as the golden treasure so well hidden among the peaks of Mystery Mountain.

A curious code used in ancient Greece provides an ingenious twist to this delightful new adventure-mystery by the author of The Secret of the McGilley Mansion.