My search shows imagery up to abt 2013. GE has a historical time slider you can see imagery back to 1998.
Search of the USGS GNIS ( Geographical Names Information) shows:
EL Capitan; ID 259807; Feature Class Summit; County Mariposa CA; Lat 374403N, Long 1193316W; El. 7569 Ft. ( Lat and LOG in DMS) Using this data you can call up the USGS data sheet and get more detailed info and it may have the lat / long to two place seconds). If you want to enter accurate SU geo location use data sheet to get the more accurate info. The Su xy data will then be referenced to that origin. You will have to open the USGS home page, look at right side for data sets, select that and enter the name , lat and long. you may get more than one but the target shown show 1 in the H_V numbers or name?
My thought: the data used is shown at bottom of imagery. What happens is user contracts with sat owner and request data processed to a certain level of accuracy. For the fast elevation changes in that area the data will not be super accurate.