Answer: In "The Rockpile" by James Baldwin, the character that first identifies the rockpile as a dangerous place is Elizabeth.
Step-by-step explanation: In the short story "The Rockpile" written by the American author James Baldwin, Elizabeth is the mother of Roy, John, Delilah and Paul as well as Gabriel's wife. She is the first character that warns her children about the rockpile, a natural outcrop that she considers to be dangerous. However, despite Elizabeth's warnings, Roy decides to go to the rockpile anyways and ends up hurt.