The time of year you book the trip will matter.
The days are longest in the summer.
In the morning the
northbound (#14) Coast Starlight is near Mount Shasta (about 5 am) though the mountain is back lit by the morning sun.
June is the month the sun rises the earliest in that area -
5:38 am from June 10 to 18.
The CS is scheduled to depart Dunsmuir at 4:56 AM and is climbing a grade between there and the town of Mt Shasta.
So it's going pretty slow. There are
a couple of switchbacks (the Sawmill Curves) that add distance compared to a straight line that also help keep the train in the area so we get a chance to see Mt. Shasta as we sip our morning coffee.
So pretty evergreen forest views in the early morning.
Just south of Weed, CA the train takes a NNE diagonal loosely following Highway 97 as it heads to Klamath Falls, OR.
A bit over 1 mile before the CA-OR border
the CS goes through an 1144 foot tunnel.
After Klamath Falls the train is still following Hwy-97 and the eastern shore of Upper Klamath Lake, a very scenic section of the trip.
After the lake Crater Lake National Park will be on the left side of the train. Crater lake is on top of Mt Scott so Crater Lake can't be seen from the train.
After Chemult the CS breaks left away from Hwy-97 and heads through the also very scenic Willamette Nation Forest to Springfield/Eugene, OR.
I've not ridden the CS past Eugene, so use Google Maps to follow the train tracks if you want to see what you'll be able to see.