There have been several reports on this forum of Big Horn Sheep sightings in the White Mountains. Here with some information regarding the Sierra Nevada and the Desert (includes White Mountains) Big Horns:
http://www.dfg.ca.gov/wildlife/Bighorn/Desert/http://www.wmrs.edu/resources/reference%...ntains/ch22.pdfhttp://sierrabighorn.org/There are a few differences between the Sierra Nevada and Desert Big horns, but mostly regarding their horn formation.
If any of you spot them, anywhere, report your sighting to California Fish and Wildlife - especially if they are tagged animals. In the Sierra's they are starting to move around quite a bit.