Silent Pal.

New Yorker David Kingston, a university student involved in the study of mine engineering, is falsely accused of theft and expelled from school. David's mother soon dies of grief, and he decides to end it all by jumping in the river. David is deterred from suicide, however, when he adopts a stray pup, which he names "Thunder." The dog later finds a map indicating the location of a gold mine, and David heads west to Northern California.