What does the 1^6 symbol indicate on certain aviation maps?

The 1^6 symbol on certain aviation maps represents the maximum elevation figure for that quadrangle. This figure indicates the highest terrain or obstacle elevation in feet above mean sea level (MSL) within that specific area. It is crucial for pilots to be aware of this elevation when planning navigation and in-flight operations to ensure safe altitude clearance over any potential obstacles, particularly in mountainous or rugged terrains.

The maximum elevation figure helps pilots avoid controlled flight into terrain (CFIT) incidents by serving as a reference point for safe climbing altitude, especially during approach and departure phases of flight. This information is invaluable for situational awareness and enhances the overall safety of flight operations.