What is the minimum altitude for IFR flight over designated mountainous terrain?

The minimum altitude for IFR flight over designated mountainous terrain is established at 2,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to ensure adequate safety margins for aircraft navigation. This altitude gives pilots the necessary clearance from potential hazards such as peaks, ridges, and other obstacles that may rise sharply in mountainous regions. Maintaining this altitude helps to minimize the risk of controlled flight into terrain and ensures that aircraft remain safely above any topographical challenges that could impact the flight. Therefore, flying at least 2,000 feet above the highest obstacle not only adheres to regulatory requirements but also promotes overall flight safety in challenging landscapes.