I have not be pleased with several areas of the north end curves and their mountains.  Time to get off the dime and wrap up this section.  The photos show added boulders and outcroppings to the scene blocks (in both the curve and the tunnel area), the lower canyon side walls, and the  curve transition between the slate walls and the tunnel wall.

The ledges will be covered with ground cover and brush.  Maybe an appropriate sized scrub tree.  Talus will be arranged at the base of the walls, and the ties and track weathered.

This side of the scene break is high desert where deciduous and evergreen trees grow.  Ground cover and brush will fill most of the voids.  Tunnel portals and retaining  walls are ready to be installed.

This is the canyon side wall leading  to the bridge. When I have the rest of the corner complete, I will create a canyon floor tied into the walls.  It will run to just past the bridge and hide the framework and ground.  This area is also ready for ground cover and select trees and bushes.