If you know the split locations (some are easily missed by first time runner) and the estimated splits to each location then a standard watch will do the trick.
But one that shows altitude can prove to be a handy way to answer the ever so important question of "how much of this thing is left." The finishing altitude is 14,100 ft (give or take a bit). You start at 6,300. At 10,200 (barr camp) you are more or less halfway there. :-)