As an eastbound BNSF stack train goes up a westbound unit tank train comes down into 'old Cajon'. This location, once Cajon Station, is where the north and south tracks split with the original 3% grade 'south track' following the original 1885 laid route (bottom right) to the summit while the 'north track' added in 1913 followed a different and lengthier course, trading distance for an easier 2.2% grade. The new third main track, added nearly a decade ago, followed the course of the north track as demonstrated here by the east-west meet at Sullivan's Curve. UP 6706 on the point of the tanks started life as C&NW 8804 and still proudly wears its as delivered green & yellow C&NW livery.