Castle Rock is located about halfway up Utah's Echo Canyon, where the tracks veer out of sight of Interstate 80 (and become inaccessible to anything less than a four-wheel drive vehicle) until just south of Wahsatch. Here the eastbound track is already out of sight, having disappeared into a tunnel, and the westbound track visible here is emerging from a rock cut that also takes it away from the Interstate. Both lines will run side by side down to Echo where they will form the UP's two-track mainline through Weber Canyon.
