The line crosses the S. Fork of the Palouse River 14 times between Colfax and Pullman. You have the burned bridge and the one that Watco repaired just enough to take the curse off after the FRA flagged it a few years ago. There are other spans that also need attention really soon, according to what I hear. Storing light-weight well cars on them shouldn't cause any problems with additional wear and tear. Some of the bridges are a combination of timber and steel.
The MAIN issue that is going to have to be resolved on the whole line package is that of status as far as traffic routing. The BNSF and the UP each consider the whole of the line segment that connects to them as "closed station" (captive). The station of Wilson (at Moscow) is the only active shipper that currently has a clear "open station" status, but due to the bridge situation, cars going there have to either be interchanged at Spokane or come BNSF all the way to Marshall. If the 2 lines are someday going to be connected together again (via either Colfax-Pullman or Thornton-Oakesdale), the status of ALL of the WSDOT-owned trackage HAS to be answered or you can't establish an interchange to take a car say from ex-BN Palouse (closed station BN) out through ex-UP Thornton to Hooper (UP mainline interchange). Nobody currently knows the official status of either line--much less the old ex-MILW W.I.M. line that the BN bought to connect Palouse (closed station BN) to the St. Maries River RR (all open station).