An eastbound Union Pacific coal load descends through the horseshoe curve encircling the mouth of Coal Creek Canyon at mile 22.6 west of Clay, Colorado, on October 22, 2012. In this view, two GE AC4400CW DPUs (Nos. 7099 and 6961) on the rear use dynamic braking to assist the train down the steep 2% grade. Moments earlier, the three lead locomotives passed this location (AC4400CW-CTE No. 5800 and two trailing AC4400CWs, Nos. 7182 and 7048), and there were no middle DPUs on this particular train.
