Railroads do not take this kind of freight anymore. Even if they did, you wouldn't want to ship your Airstream this way. I have had them severly damage my 70 ton railroad passenger cars when moved in freight trains: Broken windows, doors knocked off hinges, piano dislodged from its mountings, funiture tossed about, damaged couplers, bums set up housekeeping, 400# batteries stolen, 4/0 power cables stolen... Modern, profitable rail operations depend on long "unit" trains of long-haul commodities such as containers, coal, automobiles and produce from point A to point B and they don't want to be bothered with small, one-off loads. When they do accept a load such as a new Caterpiller roadgrader they get about $1.90 a mile.
U-Haul and Enterprise do not allow you to tow your trialer with their vehicles. U-Haul welds their 2" balls to the bumpers. If you attempt to tow with their truck, you invalidate your rental agreement and are not covered by any of their insurance.
We have a driver who was scheduled to deliver a trailer to Spokane in the near future. If he has not found a backhaul, he might be available. Send me an email at brett@TimelessTravelTrailers.com
with your contact info and I'll put the two of you together.