A detailed military account of the 1st Marine Division’s September 1944 assault on Peleliu, tracing planning, amphibious landings across coral reefs, and the heavy preparatory naval and air fires that preceded the assault. It examines the unexpectedly complex Umurbrogol coral ridgeline, the Japanese shift to a defense-in-depth strategy, and the operational consequences for Marine units, including disrupted command-and-control, intense close-quarters combat to seize key terrain, high casualties, and logistical strain. The narrative combines unit-level action, maps, and tactical analysis to explain how terrain, preparation, and evolving enemy doctrine shaped a protracted, costly campaign.