Search - Danger on Thunder Mountain (An American Adventure, Book 3)

my kids enjoyed this book. sort of like a Nancy Drew mystery
Elaine

(Back cover) Hildy Corrigan and her cousin Ruby had hardly set foot in the Mother Lode community called Simple Justice when they ran straight into trouble. Coming on the scene of a sheepherder being tormented by local boys, Hildy instinctively comes to his aid. When Ruby takes on the ringleader, the boy's uncle intervenes and ends the fight. But why, when Ruby shows them the picture of her missing father, does this wealthy cattleman appear to recognize him, then quickly deny it? And why is someone trying to stop them from finding him--even going so far as to put their lives at risk?