What does a benchmark indicate on a map?

What does a benchmark indicate on a map?

• A. A point whose elevation has been precisely determined
• B. A point used to measure distance
• C. A contour line with labeled elevation
• D. A location of a water feature

Answer: (A)

In surveying and mapping, a benchmark provides a fixed point on the land where the exact elevation above a standard reference (like sea level) has been determined with high precision. This vertical control point acts as a reliable reference so that elevations across the map can be measured consistently—leveling from the benchmark or tying GPS elevations to it ensures all height measurements line up with a known standard. You might see benchmarks marked on durable markers or disks with a stamped elevation, serving as the anchor for other measurements in the area. The other ideas describe different map features: a point used to measure distance is about horizontal measurement, not an elevation reference; a contour line with labeled elevation represents a line of equal elevation, not a single fixed point; and a water feature location marks a place on the map where a water body exists, not a vertical reference point.