Notwithstanding the severely broken character of the Rockies, he decided to drive his railway almost in an air-line. The surveyors pointed out that approximately 75 per cent. of the track could be laid along river banks threading the mountains where grades and curves could be kept tolerably easy. The greatest and costliest features of the scheme was the double toil over the Great Divide. The mountain ramparts practically lock Denver in upon its western side, and the railway makes a direct plunge into the mass. The South Boulder canyon affords the causeway for the railway through the first clump. Certainly the gorge is well named, for its sides are ragged in the extreme, precipitous, and strewn with ugly, projecting masses of rock. Being unhampered financially, the engineers were enjoined to carry their work out upon the most solid lines. Timber trestling across clefts on the hill-side was to be avoided; the line was to be carried well above the river, and in such a manner that easy alignment was secured. This involved keeping well into the side of the mountains, only to meet obstacles in the form of massive humps of rock projecting from the slopes. They could not be blasted away--the only solution was tunnelling. Consequently, the train plays a game of hide-and-seek as it darts in and out a chain of tunnels. In the course of 13 miles there are no less than 30 tunnels through these spurs, ranging from 73 to 1,720 feet in length, and aggregating 16,000 feet in all. It was the constant recurrence of these tunnels that provoked a querulous traveller to ask why the engineers did not “tunnel the range the same as they do in the Alps and have done with it?” In order to fulfil the demand of the “Silver King,” heavy excavation was inevitable. The rock thus removed was put to useful account to fill crevices and rifts to avoid trestling. It was expensive construction, but at the same time it ensured an excellent permanent way--permanent in the fullest sense of the word. [Illustration: _Photo by courtesy of American Locomotive Co._] THE GIGANTIC SNOWPLOUGH, THE LARGEST YET BUILT, WHICH KEEPS THE HIGHER LEVELS OF THE “MOFFATT” LINE THROUGH THE ROCKY MOUNTAINS FREE FROM THE HEAVY FALLS OF SNOW]