The hours at Mt. Bachelor were short when I skied there May 3-4, 1990, so the long-standing policy may well have been to shorten hours at the same time lift operations were cut back. Not sure if April 20 has been the typical cutback date; I think Northwest was open weekends to first weekend of May in a couple of big years.
Under Dave McCoy Mammoth ran everything through last weekend of April, which coincidentally tends to be a big tourism weekend because of opening of Eastern Sierra fishing season. Since Intrawest last full op weekend appears to be later of 3rd weekend in April or weekend after Easter.
Mammoth's commitment to the Memorial Day and beyond season seems just as strong as under McCoy. While they require Broadway to be skiable, Broadway has a snowmaking base that keeps it open longer. And Mammoth expends considerable effort building an upper mountain terrain park for just the few weeks after the one near Main Lodge melts out. There were more skier-packed lines off the top in June/July of 2005 and 2006 than in the big years of the 80's and 90's, probably due to chair 23 being open more.
Under Dave McCoy Mammoth ran everything through last weekend of April, which coincidentally tends to be a big tourism weekend because of opening of Eastern Sierra fishing season. Since Intrawest last full op weekend appears to be later of 3rd weekend in April or weekend after Easter.
Mammoth's commitment to the Memorial Day and beyond season seems just as strong as under McCoy. While they require Broadway to be skiable, Broadway has a snowmaking base that keeps it open longer. And Mammoth expends considerable effort building an upper mountain terrain park for just the few weeks after the one near Main Lodge melts out. There were more skier-packed lines off the top in June/July of 2005 and 2006 than in the big years of the 80's and 90's, probably due to chair 23 being open more.