From the foregoing description of the most favorable mountain passes, it will be seen that Sugar Run Gap offers the greatest facilities to cross the Allegheny. It now becomes necessary to consider in what direction the Road can be carried thence to Pittsburg. From an inspection of a map of the State it will be seen that a straight line, drawn from this gap to Pittsburg, will fall on Munster, Beulah, and follow the valley of Black Lick for nearly its whole extent, and intersect the Conemaugh near Blairsville; thence it crosses the country lying within the elbow formed by the Kiskeminetas and Allegheny rivers, passing the Loyalhanna and Crabtree waters, and following, generally, the high and broken ridge parting the Allegheny and Monongahela rivers. That line, which would approximate most nearly to this course, would--all other things being equal--be the most desirable for the Road. The operations of the different corps, on this division, have been confined to surveys that were necessary to determine the point of crossing the mountain and to the regions between the Conemaugh and Pittsburg, west of the Chestnut ridge. Our examinations have not yet been sufficiently extensive to enable me to give a full description of that part of the country between the mountain and Blairsville, and I shall therefore leave it for a future report, with the simple remark that, from the information before me, I am satisfied that a practicable line may be obtained by the valleys, either of the Black Lick or Conemaugh, within the maximum gradient used upon the western division. The district of country over which it will be necessary to carry the road from the Conemaugh to Pittsburg is one of remarkable intricacy. It lies wholly within the coal measures, and has, at some period, evidently been nearly a level plane of vast extent, covered by the ocean. The discharge of the waters from this wide spread field seems to have been sudden, forming numerous circuitous channels in every direction, cutting deeply into the soft horizontal strata of this region, in their descent to the tributaries of the Ohio, leaving the intervening ridges washed into so uneven a surface as to render the passage of a railroad along them entirely out of the question. A line following the Conemaugh--which bears northwest from Blairsville--to the Allegheny would avoid this difficult country, but the length of the route would be increased fully 50 per cent., and it is, therefore, inadmissible. A route with higher gradients than those adopted on the Juniata throughout this division seems to be called for by the topography of the country.