It's been more than a year, I wouldn't expect tracks to last that long. I would be surprised if they found anything. Even a plane could be overgrown in that length of time. I could be wrong though.
Angel I concur that tracks likely won't be found but altitude and climate preserves artificial materials (fleece, airplane fabric) really well. The plants grow very slowly so the plane won't be overgrown. (it could if it were in the deep South but not in the Sierra) It might be embedded in snow though.
See my website :
http://coloradowreckchasing.com for indications of how well wreckage lasts at altitude.
I don't think it will take long to solve the mystery now.
Just FYI- the card labelled SSA with his name on it is from the Soaring Society of America - a glider organization that recognizes records in gliding. Fossett set several glider records during his career.