In April of 1983 a mudslide inundated the town of Thistle, UT as well as the Rio Grande tracks. For nearly three months, the Rio Grande was forced to use the UP from Denver to Ogden until a new alignment and tunnels could be constructed. Since UP was cab signal territory, UP leaders were required. As such, UP 3495 leads three D&RGW SDs on a coal train that would normally have run over Soldier Summit but has come the long way around through Wyoming. The crossover here at MP 941 marks the point where the tracks separate to the top of the grade at Wahsatch. The westward track, on its early alignment and steeper grade, passes above the eastward track at Curvo, thus it is left-hand running from Curvo down to Peterson in these Rule 251 (current of traffic) days. UP train dispatchers each received a basket of Colorado peaches for their trouble in handling the additional traffic; yet the Rio Grande detours were always powered up and moved right along.