Discussions regarding the height of Mt. Whitney or for any peak must take into account the order or degree of accuracy of the survey disc. For example, and this is a fact, vertical control markers and their orders (not to be confused with vertical angle) have precedents over horizontal control markers regarding height. Survey disc GTO237 is a third order vertical control and is therefore a highly accurate vertical control marker. If this is not the case, then all the other elevations on Whitney come into question. GTO237 is one of the most accurate markers regarding height but not all that accurate regarding horizontal control. But who really cares about horizontal control measurements when the discussion is about the height of a prominent mountain. Horizontal control is not as accurate as vertical control. Yes there are other vertical control markers on Whitney, but they are crowed together in a small area away from GTO237 and of course not as high. It would be best for these discussions regarding the height of Mt. Whitney to take into consideration the various geodetic controls and their accuracy. Again, no mention is made in your article of survey marker GTO237, which indicates 14,502.7 ft. (14,496.5 + 6.15). As far, as the USGS, indicating 14,491ft for Mt. Whitney on their 1989 provisional topo map, that elevation is misleading and has only greatly added to everyone’s confusion.