The 1877 arrival of the railroad in Georgetown was quickly overshadowed by massive silver discoveries in Leadville, forty-five miles to the southwest, which touched off a rush to the new ore fields. Seeking to share in the bonanza, the Union Pacific Railroad proposed several routes to Leadville, including one west from Georgetown across the Continental Divide at Loveland Pass. Surveys of that route were made in 1879, and two years later the Georgetown, Breckenridge and Leadville Railway was incorporated. Its greatest obstacle stood just outside Georgetown, where Clear Creek Valley rises almost 640 feet in under two miles, creating a grade of more than 6 percent, too steep for most locomotives. Union Pacific Chief Engineer Jacob Blickensderfer solved the problem by designing a route that reduced the grade to 3 1/2 percent: at Devil's Gate, the valley's narrowest point, the track made two hairpin turns and looped over itself above Clear Creek, then continued up the valley, crossing the creek twice more and climbing through a 30-degree horseshoe curve called the Bill Fill. After three years of construction, the Loop was finished with the high bridge, and the first train followed its winding course to Silver Plume in March 1884. By then Union Pacific lines had already reached Leadville by an easier route farther south, so plans to carry the Georgetown line over the Divide were dropped. Even so, the Loop captured the American imagination, drawing tourists from around the world to Georgetown and over the line to Silver Plume, where visitors could continue on the Argentine Central Railroad to the top of Mount McClellan or ride the Aerial Tramway up Sunrise Peak. For about forty years sightseers came, but visitation declined after World War I, and the automobile helped bring an end to the Denver-to-Silver Plume excursion line. In 1939 the Colorado and Southern closed the road and removed the track, ending a notable chapter in Rocky Mountain railroad history.