When the Mountain Came to Miramar is a science fiction novella by American author Charles W. Diffin.

It is magic against magic as Garry Connell bluffs for his life with a prehistoric savage in the heart of Sentinel Mountain.

When the Mountain Came to Miramar was first published in Astounding Stories, March 1931.

Total Running Time (TRT): 1 hour, 4 min. Reading by Catherine Russell.

Charles W. Diffin (1884-1966) was a US engineer, airplane salesman and science fiction writer. He was one of the better writers whom Harry Bates encouraged to write for the new Astounding Stories.