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The eastward main is in the foreground and Extra 5637 West is on the westward grade up to Ash Hill. The date is July 15, 1979. Only the first two and last two units are online. Just west of Siberia the east and westbound tracks split. The westbound track takes 9.5 miles to climb up to Ash Hill while the eastbound track takes only 7.7 miles to drop down to Siberia. After CTC was installed the tracks are referred to as the north and south tracks. The south track has grades up to 2.0% while the longer north track keeps the grade at an almost steady 1.44%.
Just a little bit earlier that same afternoon, train 388 (Extra 5050 West) traverses the same fill and curves to the east for the climb up to Klondike. Disk 49