On the western hills of Eagle Valley, a single spot stands out where the slopes meet the sky.  The rocks that form the letter "S" are a mystery to some, but to 96-year-old Hilman Tobey, the symbol is a haunting and historic memory of his childhood and the community that nurtured him in the early 20th century. In 1934, Tobey was a sophomore at the Stewart Indian School and was part of the class that built the landmark.  Tobey learned to be a carpenter, a skill that would support him the rest of his life.  That's why he and his …