US forces closed the "bulge" on January 15, 1945, when they linked up near Houffalize and by early February the lines had returned to their pre-December 16 position. Pressing forward on all fronts, Eisenhower's forces met with success as the Germans had exhausted their reserves during the Battle of the Bulge. Entering Germany, the final barrier to the Allied advance was the Rhine River. To enhance this natural defensive line, the Germans promptly began destroying the bridges spanning the river. The Allies scored a major victory on March 7/8 when elements of the 9th Armored Division were able to capture intact the bridge at Remagen. The Rhine was crossed elsewhere on March 24, when the British 6th Airborne and the US 17th Airborne were dropped in as part of Operation Varsity.