85 FAA Chart Users’ Guide - IFR Enroute Symbology Airspace Information (Continued) AIRSPACE - U.S. CLASS G  High and Low  Chart Uncontrolled  Airspace Screened Brown Area Low Altitude That portion of the airspace below 14,500’ MSL that has  not been designated as Class B, C, D or E Airspace. High Altitude That portion of the airspace from 18,000’ MSL and above  that has not been designated as Class A airspace. Example: CLASS B  Low Charts Only Controlled  Airspace Screened Brown Checkered Area Controlled airspace above 12,500’ MSL Example: AIRSPACE - CANADIAN