The more I look at this chart, the more I am perplexed at how they calculated the Kilometers of slopes... For instance, they are saying that Aspen Highlands is technically bigger than Mammoth!? My gut tells me no way, and I've been to both. Just look at the trail maps.
Found this on reddit and not that it really answers the question but it’s interesting
Park city is huge, and not a lot of easy and not that much really difficult eather
Thing about ratings, they’re relative for a given mountain. So a green on a really challenging mountain might be a black on an easy mountain
But still, interesting
The numbers are slope length in km, not number of runsView attachment 104075