By 1903, the tracks reached the Tolland area just east of the Continental Divide where Sumner's second major engineering feat involved crossing Rollins Pass at an elevation of . Originally, Moffat had planned to build a tunnel underneath the pass but funding was not available at the time. The DN&P climbed to Rollins Pass using a series of switchbacks with a 4% grade at many locations; tunnels at various places as well as huge loops were also needed so as to get over the pass. At the time, it was the highest mainline railroad ever constructed in North America; Rollins Pass was entered into the National Register of Historic Places in 1980 for its railroad related engineering feats. Small rail stops at Corona at the top of the pass and at Arrow, 11 miles to the west, had restaurants and lodging which housed workers keeping the rail line free of snow in winter. Despite this, trains were often stranded for several days during heavy winter snows.