This is ARR 2501 a northbound out of Whittier. This train waited at Portage for the Whittier Shuttle to overtake it. The Shuttle was heading to the passenger siding at Portage.
 
While the 2501 was waiting for the Shuttle I was able to hike out of Bear Valley, get back in the car, overtake the train, and then get in position for this shot.  The train started moving before I could get to my preferred spot, so I had to 'settle' for this location.
 
This picture is just north of the Twentymile River Bridge, as seen in February 1986.