Which statement describes a primary use of a Grade Stake?

A Grade Stake is primarily used to provide a reference for the construction's elevation. These stakes are typically placed at significant points in a construction site to indicate the desired height or elevation of different structures, such as roads, foundations, or grading levels. By utilizing Grade Stakes, contractors and surveyors can ensure that all elements of the project conform to the specified design elevations. This aids in achieving proper drainage, structural integrity, and alignment of various components.

In contrast, while the other options involve important surveying tasks, they do not accurately capture the primary purpose of a Grade Stake. For example, indicating where excavation should start is an action that might be related to site planning but does not rely on the Grade Stake's function of marking elevation. Similarly, defining boundaries of a surveyed area involves property lines and markers, which are distinct from elevation markers. Lastly, measuring distances in a grid system pertains more to layout and planning rather than the specific use of Grade Stakes in relation to elevation.