Yard and Industrial Area Tunnel Portals

Most recent work on the railroad has been on the mountain's tunnel portals near the yard/industrial area of the layout.  Everything is now fairly stable and planned out; the detailing work needs to be completed.  More ground cover is needed on the mountain, bigger trees needed in front of the portals, and some more detail added to the vines/brush growing around the portals on the mountain.  Longer term plans: the blue drape background can be replaced with a painted background, and a retaining wall could be built coming out from the edge of the double portal and running along the edge of the layout.  Maybe add some signals at or near the portals?