A post by Nick W. on the Altamont Press forum (here) indicates that the Central California Traction Company (CCT) has just retired its GP18 #1790.
It was built as Rock Island #1343 in February, 1960, and I think it came to CCT in 1981. Pretty long career for this Geep, and it certainly looks good.
I haven't read any preservation news about it yet. Maybe there is something happening behind the scenes? I guess we will have to wait and see.
Recent photo:
http://www.rrpicturearchives.net/showPi ... id=3982680
Sister unit wearing Rock Island colors in the 60's:
http://www.railpictures.net/photo/494172/