Why did the Union Pacific stopped using the Modoc line.
There are other ways UP can get freight to and from the northwest and avoid using the Modoc Line.
Generally speaking, railroads eliminate trackage they find redundant. If there are two ways to connect two points, they will eliminate one of them if there is not enough traffic to support both. The line judged least efficient will be the one to go, taking into account operating conditions like comparative mileage, curves and grades, age of the physical plant, capacity and potential for online traffic.
I do not know all the specifics of Modoc but it has been discussed at length on this and other forums. It traversed some beautiful country and was a favorite of a lot of railfans. I'm sure someone will respond with more detail.
John Timm
It was jointed rail and dark territory with no on-line businesses to justify its operation. I think the SP had let it deteriorate too much to be economically viable. In one video I have about the Modoc line that was shot right before it was closed, "Extreme SP" by Charles Smiley Video, there were even cattle roaming on the track.