What high school in the US holds national record 4x400m relay?

There isn't a single, officially recognized national record for high school 4x400m relays in the US. Different organizations (like the National Federation of State High School Associations (NFHS) and others) may track records differently, and records are often unofficial unless set at a specific, major championship meet. Therefore, there's no definitive answer to which high school holds a universally acknowledged national record.