White Truffle in Oregon?

I think this is a truffle. Very heavy. Was growing near rose bush. If not a truffle what is it?

Was it above ground, or did you have to dig it up? True truffles, members of the Tuber genus, grow underground. If it was above ground, it could be a puffball of some type.

It doesn't look like either a T. oregonense or a T.gibbosum (Oregon white truffles) Based on this one photograph, I believe it may be Elaphomyces granulatus or Scleroderma cepa. If we could see the interior, that would help further identify it. What does this specimen smell like? If you cut it and examine the interior, it would help establish a more positive identification. You can refer to these links:
http://www.natruffling.org/scce.htm
http://www.natruffling.org/elgr.htm
http://www.rogersmushrooms.com/gallery/DisplayBlock~bid~12098~gid~~source~gallerydefault.asp
http://academic.evergreen.edu/projects/mushrooms/mtsm/s43.htm