Final answer:
Topographic maps are essential for navigating unmarked wilderness areas and provide valuable information about the Earth's surface. They are less necessary when following marked trails. These maps help with locating and identifying various features, and provide important details about potential hazards.
Step-by-step explanation:
Topographic maps are essential when heading for unmarked wilderness areas. They are useful, but less essential, when sticking to marked trails. Topographic maps allow a person to locate and identify features on the Earth's surface such as hills, valleys, depressions, steep cliffs, and gentle slopes. They also provide information about geologic hazards like landslides and flooding. These maps are useful for activities like purchasing property, landscaping, planning a hike or camping trip, or surveying an area for construction.