Son of William J. and Elizabeth Muncaster. Brother of John, William, James, Elizabeth, Edith and Ethel. Worked as forest ranger in Seattle. Member Company D, 6th Battalion, 20th Engineers. Was among Forestry troops that supplied lumber for dugouts, trenches, and entanglements and military facilities. Killed in sinking of transport shop Tuscania, first American troop ship torpedoed and sunk in the war, and was among the 489 American soldiers lost who washed upon the shores of the Island of Islay after sinking of Tuscania and Otranto. Muncaster worked with Sergeant Everett Harpham and others to successfully get lifeboats launched into the water despite no training for the task. Muncaster and Harpham successfully boarded the last lifeboat but died when it was dashed upon the rocks. After the war all the Tuscania soldiers were exhumed except Muncaster whose family requested that he remain undisturbed. The people of Islay ensured his grave would be treated as if he were one of their own, now maintained by The Commonwealth War Graves Commission, very unique as they do not usually maintain graves of non-Commonwealth casualties. Muncaster Mountain in Quinault, Washington named for him.