Why do contour lines point uphill when they cross a stream?

Contour lines point uphill when they cross a stream due to the topographic representation of elevation. As water flows downhill, the contour lines indicate changes in elevation; when they intersect a stream, they form a V shape that points upstream. This orientation shows that the higher land lies in the direction of the point of the "V," indicating that the elevation increases as you move away from the stream. Thus, the V shape helps visualize the relationship between the stream and the surrounding terrain.