Bob and WB. I'm reposting the letter from page 2 of this lengthy thread, from the father of the deceased, Michael Powell. There is another letter going around as well to the Forest Supervisor. So Inyo is well informed at this point and some official response will probably be forthcoming to improve the trail navigation in this area. In addition, the Search and Rescue team should also be following up with Inyo NF regarding their impromptu trail work at this spot (which is NOT a violation of the Wilderness Act).
If you're truly concerned about people moving small rocks along the trail, perhaps you two could use your experience and contacts to organize a properly sanctioned trail improvement. Its probably going to happen either way, but your support would be welcome.
As I said to Steve, I do my bit in SoCal and do not have the time to spend in the Sierra because of family issues.
Bob West just told you how to get things done. Why don't you either stop in WMRS or call the volunteer coordinator and tell him you want to volunteer for any work on the MMWT in the Mirror Lake area.