Previously Unpublished Battle of the Bulge Photos

From mid-December 1944 through the end of January 1945, in the heavily forested Ardennes Mountains of Belgium, thousands of American, British, Canadian, Belgian and French forces struggled to turn back the final major German offensive of World War II. While Allied forces ultimately triumphed, it was an absolutely vicious six weeks of fighting, with tens of thousands dead on both sides. Today, the conflict is known as the Battle of the Bulge.
Here, 70 years after the start of the Ardennes Counteroffensive (as the battle is sometimes known), LIFE.com presents a series of photographs made by LIFE photographers throughout the fighting. Many of these pictures never ran in LIFE magazine.