After the new 1985 design for The Oregon Trail appeared on the Apple II, MECC soon ported the same identical design to several other home computers, although in each case the graphics had to be redrawn. I believe that the Commodore 64 was one of the half-dozen computers that were targeted. (I know for certain that MECC converted several other products to the Commodore 64.) However, based on your question, I’d like to find some documentary proof to verify my recollection.
UPDATE: So far, and contrary to what I had thought, I don’t see any evidence that the 1985 design was ever ported to the Commodore 64. Instead, I see that the older 1980 design was ported over to the Commodore — a version that was essentially identical to the original text-only game. If I run across any additional information, I’d add another update.