Possible Clues:

• Chain letters?
• Range: Abbr.
• High-elev. places
• Chain components: Abbr.
• Range components: Abbr
• Everest and K2: Abbr
• St. Elias, in Alaska
• Range units: Abbr.
• Calif.'s Sierra Nevadas, e.g.
• Ski areas: Abbr.