When will Rocky Mountains ski resorts open for the ski season? The 2026/27 Ski season at Rocky Mountains resorts starts from 09/10/2026. See this list of projected opening dates for Rocky Mountains mountains. Important Note: Not all dates listed here are official and final, as resort opening dates are projected and subject to change. Check back for updates on when the lifts are set to start spinning at Rocky Mountains resorts, and don't miss opening day at your favorite resort!