No, you've got it backwards. Going eastbound you start out on the southern side of the gorge no matter what, putting the gorge on the left side of the train's forward motion. IIRC, there are two places where the train can cross the river. If it takes the earlier bridge, then about 1/2 to maybe 2/3rds of the gorge is on the left, the rest on the right. Generally however they take the second bridge, which puts about 90 to 95% of the gorge on the left of the train.