The UP tracks come down Echo canyon with I 80 close by and at Echo turns down Weber Canyon. At Echo I 84 branches off 80 and closely follows the UP tracks westerly to Ogden crossing it twice. The Challengers and Big Boys were built because of the eastbound bottleneck between Ogden and Wasatch Utah just west of Evanston Wyoming. Due to the fact there was no room to cheaply build another eastbound line beside the double track main line they chose bigger locomotives as they reduced the extra locos too. Eastbound is 1.4 but westbound has some 1.8 spots.
Just south of Ogden the tracks turn south to Salt Lake City then on to LA.
I missed the Transcontinental Sesquicentennial Celebration due to health problems. Winter of 2017-18 I did radiation and Chemo for prostate cancer which they had missed a few cells in 09 when the prostate was removed. The PET/CT scan had more to say about my degenerative disk disease than the cancer so I can not stand long or my back kills me. The chemo shuts down the tosterone production which was still 190 on Aug 25 when low is 300 ( PSA is still undetectable). I didn't feel I had enough energy to brave the crowds in Ogden or at the NMRA Convention.
I went up where dads property was by the ledges on the hill above old US 30 south when 4014 and 844 came west. Found a video that was shot from Henefer off ramp and you could see me silhouetted in the steam cloud on the mountain as they came around the point west of Echo. Went back up when they came east but stayed by old 30S that time.
I watched hundreds of trains pass while riding formly horse drawn farm equipment pulled by dad on the case tractor where 84 is now.