Nope. In 1996, after the Rio grande had bought out the SP, but kept the name (Except for their home state of Colorado), the SP had some pretty big finacal issues. They were in a weak state, and since the merger between ATSF and the BN had just gone threw(I belive in 94) and the UP was looking for a way to gain a competitive edge on the BNSF, if not just to stay alive. So, they looked at their long rival, the SP(Now owned by the DRGW i know) and saw they could eat it up and not be eventualy over run by the BNSF. But it didnt go so smothly. It even got so bad that some SP records were lost, and for a time there were actualy a number of "Ghost" locos on the newly aquired UP trackedge. Not to mention stock problems, etc, etc...
But in short, no. UP bought out the SP, and that is fact.