If you can, try and sit on the left side going up. Why the difference? On the right side you will be looking at the side of a mountain. The tracks are carved into the hillside. The reason it does make a differnce is that going up you will be able to see and follow the narration . Going down you will be able to see, but, there will be no narration .
It DOES make a difference. From Skagway sit on the left facing the engine, from White Pass sit on the right. The significant reason- MOST of the commentary is on the way UP the pass, from Skagway. It is far BETTER to be able to see what they are taking about at the time, instead of constantly jumping up from your seat to see.
I just returned from my Alaskan curise. Yes, you get most of the commentary on the way up, making the left side the best for the first part of the trip. But not many people spent much time sitting. Most of us spent time rotating on and off the platforms and standing inside the cars looking at what was being talked about by the commentator.
On the way back down there was a lot of repeat commentary with new information added.
We just returned from Alaska...we did the 4:30 train ride. The train was almost empty and about ten of us had an entire car to ourselves. We weren't fighting for a space outside (there's not much room outside!) and we all got a window view on the way up or down. We had plenty of time to get back to our ship for departure.
We did a hike and float in the morning and it was AWESOME!!! I would recommend both.
Someone had told us to sit by the bathroom and that way you have the same seat going and coming,which we did,but we still had to change sides,so maybe our car was different from others.But,it made NO difference since it was family on both sides and we didnt mind triping on each other if there was something out that we wanted to see....I would still recommend this seating area though,since you do have room to stand between the seat and the stove.I went outside a lot,so I loved having the stove there and on.Each car had the choice of weather or not they wanted to keep the stove on.It was VERY cold outside even with hat,gloves,layers and a down jacket,so the stove was nice to come in and warm up to.We had about a min and a half of mist,other than that,the weather was wonderful! Dot