Which mountain pass should we take from Crater Lake to Eugene in December?

Thanks for your question. Both 230 (leading to 62) and 138 can be equally snowy in December, but also equally easy to traverse, given conditions. For that reason, I would go with 138, which is your more direct route, knowing that the first 25 miles or so from Crater Lake will be at the highest elevation, and most likely to be snowy, should there be snow. That said, weather casters are currently predicting a pretty dry December, so you’re likely to be in for smooth sailing. You can also check ODOT.com before your trip; I find their live cameras to be helpful! Best of luck!