The widely successful map service from Google has begun making the transition from focusing only on roadways by expanding their coverage to alternative terrain. Back in November of 2012, their first wave of ski resort coverage was added to the service. This time around 38 more ski resorts have been included in the service and are now live for your convenience.
Ski runs viewed through Google Maps are color categorized by run difficulty. The red dotted lines on the other hand mark the ski lifts. More ski resorts are said to be in the works, but likely won't be able available for use until next Winter.
The growing list of mountain maps now available in Google Maps is here: