Vail Resorts says lift ticket revenue, skier visits and spending at its six resorts are up so far this ski season. The Broomfield, Colo.-based company acquired Northstar-at-Tahoe in October and also owns Heavenly in the Lake Tahoe area, plus Vail, Beaver Creek, Breckenridge and Keystone in Colorado. It says that through Thursday, skier visits were [...]