One would think the ex-NYC, now CSX, "Water Level Route" would be the "proper" routing for a Chicago to Selkirk train. However, it is not unusual for railroads to route lower priority freight along alternate routes, perhaps those with lower traffic density or better clearances.

I can't speak for CSX, but a good example from my neck of the woods is BNSF freight in the Seattle-Chicago corridor, particularly between Spokane and Seattle. The most direct Spokane-Seattle route is over Stevens Pass and the "famous" 7-plus-mile-long Cascade Tunnel. However, this line has limited capacity, primarily due to the fact that ventilating the tunnel sufficiently after the passage of one train requires about an hour. This limits the total number of eastward and westward trains to 24 per day. For this reason, it's in BNSF's best interest to use this route only for the hottest trains in the corridor.

Fortunately, BNSF has two other options for Spokane to Seattle traffic. As a general rule, all lower-priority freight headed to the coast goes via the former SP&S Columbia River line (also a water-level route). This line also handles heavier, lower priority eastbound loads. And, for eastbound empties, most often empty grain and coal unit trains, the Stampede Pass route is used. In fact, right now, the only westbound trains running along the Stampede and Yakima River subdivisions at all are two local trains. Otherwise, all trains using the route are eastbounds.

So, sorry for the lecture, but there can be a lot of good reasons why CSX might choose to use Sand Patch for a Chicago-Selkirk train.

Or, EHH got another stupid idea and imposed it on his minions under thread of firing (or worse).