About The Blue Mountains is a section of track on the Oregon division mainline and goes for 205 miles (330 km). This line runs through multiple valleys, crosses 2 rivers and numerous creeks and climbs the crest of 3 summits. This route would run from Hinkle to Huntington. Trains operating on this line can vary from 1000 us tons to 14000 us tons (907 - 12700 metric tons). This line is operated by Union Pacific. In my opinion, this should be set in the 1990s - 2000s era. Rolling stock GE Dash 8-40C GE Dash 8-40CW EMD SD60 EMD SD60M EMD SD40-2 All information for this post came from this video
If made these will layer to Sherman Hill and Cane Creek. On Sherman Hill two Dash 8-40C equal 8k hp 3 of them 12k hp 4 16k hp enough for the consists 11k hp if Dash 8-40c SD40-2. The later date the Union Pacific Dash 8-40C will then receive reskins for CN Oakville Subdivision and CSX Sand Patch Grade.
