Action & Adventure, Other, Fantasy & Magic, Fantasy 

The Time Spies summit Mount Rushmore!The Chapman kids travel back to 1934 where they meet Gutzon Borglum, sculptor of America's greatest engineering and artistic marvel, Mount Rushmore. When the Time Spies arrive, Borglum's in trouble. His massive sculpture of Jefferson has cracked and a mystery is afoot that threatens to scuttle the entire project. Can the Time Spies find a way to save an American masterpiece? In each Time Spies book, after a mysterious new guest arrives at the inn, the spyglass whisks the children back in time to meet both famous and unsung heroes from America's past. At the end of each story, the kids arrive home to find a letter which offers fun facts about the adventure and suggests a mission readers will want to try. In this ninth title, the Time Spies solve a mystery on Mount Rushmore and meet the mountain's famous creator, Gutzon Borglum. - from Amzon