How often is a correction line made to keep range lines nearly six miles apart?

A correction line is instituted in land surveying to account for the curvature of the Earth and to ensure that range lines, which are vertical lines in the Public Land Survey System (PLSS), remain nearly six miles apart. This system is vital for maintaining accurate land boundaries and spacing as surveying occurs over large landscapes.

The correct interval for a correction line is indeed established at 24 miles. This is because every 24 miles, adjustments are necessary to ensure that the range lines, which theoretically should be six miles apart, remain so despite the earth's curvature. When mandated corrections occur, they effectively prevent the misalignment that naturally arises over greater distances between the survey lines.

In contrast, the other options represent distances that do not correspond to the standard correction line intervals used in the PLSS. Using any of those would result in inaccuracies in land surveying over extensive areas, which is why they are not applicable in this context.