What altitude would Class G airspace typically begin above in a mountainous region?

Class G airspace typically begins from the surface in uncontrolled airspace, which is especially true in mountainous regions. This characteristic means that pilots can operate without a specific ceiling for Class G airspace, allowing for flight into and above terrain.

In mountainous areas, starting from the surface is crucial because the terrain can vary significantly and can often exceed the typical elevation of surrounding areas. Allowing Class G airspace to begin at the surface helps facilitate access for aviation operations, particularly in regions where there might be limited air traffic control and the elevation of the ground varies widely.

While other options, such as beginning at 1,000 feet AGL or 2,000 feet AGL, could apply to different classes of airspace or specific conditions, they do not accurately reflect the standard for Class G airspace. Hence, the surface-based initiation of Class G airspace is essential for providing the necessary operational flexibility and safety in mountainous terrain.