Yes, I understand the old SP line is lightweight (museum-quality) & swervery ... and that's age- and current usage-appropriate. Made sense for UP to keep the better line back when things were being rationalized. But if they and/or ACE take it back, is there any reason why some cuts couldn't be enlarged and fills redone to straighten things out enough for, say, 40-50 mph operation? UP would have to put money into it anyway to bring the track and signals up to reasonable standards for a running track. I kind of agree with Bob - taking the line back and doing it up right as a 2nd main track might not be cost-competitive with just double-tracking most of the existing line - widening tunnels or not. But leaving it as essentially a glorified yard track to park freight trains on during commute periods might require less work.

In any case, it's pretty clear that if UP recovers the line it will no longer be available for an apparently at-will museum tenant on the county's property. That's still, of course, an "if" not a "when," and a lot depends on the money supply and politics.