The Los Angeles & Salt Lake Railroad was taken over by the Union Pacific on April 27, 1921, but wasn't officially merged into the UP until January 1, 1988. Here, on an abandoned bridge on the old Anaheim Branch we see the Arrowhead logo of the "Salt Lake Route." I've since been informed (by Chris below) that this portion of the bridge has been razed. A former UP rail informs me this branch was originally intended to go all the way to Orange.