Trying to Decide on what rolling stock I want.

[SleeperN06]

I guess this was a stupid question. Now that I think about it, I'm sure a large manufacturer would ship a large group of boxcars or Auto Carriers across country. I now remember my brother-in-law who works for Conrail told me once that sometimes he would be called out to certify a train or a single car from another R.R. to run on Conrail tracks.
When I first started my layout last year I want to be very realistic, but due to the limits of my layout size I realized that I couldn't do everything I wanted and that a great deal of imagination would be required. The combination of cars that came with my starter set just doesn't look right.

[Dallas Model Works]

That's the joy of freight cars -- you can mix them up.

Sounds like you're doing the present day, era-wise.

Many freight cars travel just about anywhere in North America unless they are dedicated to a specific service.

I've even seen a UP loco lashed-up with CN locos up in southern Ontario.

The only question is, how "realistic" do you want to be?

 

[2-8-8-0]

Im sure they would, since i see UP and BNSF cars up here all the time. I think nowadays cars pretty much travel wherever they are needed, with little regard to what road actually owns them.

[SleeperN06]

I'm just starting to build a collection of N-scale rolling stock and I can't make up my mind what I want. I have a very small layout so I'm limited to how many cars I can have. I have a small assortment of box cars now, but I like the looks of long groups of similar cars. I live in the High Desert of Southern Calif. and my railroad is BNSF, Santa Fe and Union Pacific based on what I see around here.
I like some of the box car colors from other RRs and I was wondering if I should limit myself to only those from BNSF or Union Pacific.
Would box cars from say Illinois Central or Chicago & Northwestern travel into Southern Calif.?