How are charted U.S. National Parks and similar areas indicated?

Charted U.S. National Parks and similar areas are indicated on aviation sectional charts with an outer solid blue line and a dotted line inside. This method of representation helps pilots quickly identify the boundaries of these protected areas, which are critical for avoiding airspace violations and ensuring compliance with regulations regarding air traffic over these regions. The outer solid blue line marks the boundary of the national park or similar area, while the dotted line inside typically signifies specific features or limitations related to airspace use. This visual representation is essential for pilots to recognize and respect the designated airspace, particularly when near popular destinations or areas with restrictions.

Other options might suggest different interpretations, but the solid blue outline with a dotted line is standardized for clearly marking these regions on sectional charts, allowing for safe navigation and respect for wildlife and environmental preservation efforts.