Airline Pilot Question:

It's an altitude derived by Jepp or provided by state authorities. If derived by Jepp, Grid MORA clear all terrain and structures by 1000' in areas where highest elevations are 5000' MSL or lower. MORA values clear all terrain and structures by 2000' in areas where highest elevations are 5001' MSL or higher. Grid MORA (State) altitude supplied by the State Authority provides 2000' clearance in mountainous areas and 1000' in non-mountainous areas. Also... a +/- denote doubtful accuracy but are believed to provide sufficient reference point clearance.