N.H. Rev. Stat. Ann. § 245:3

Persons authorized to construct and maintain a railroad as provided in RSA 245:2 shall locate the route for their railroad where they deem it most suitable, establishing at convenient distances, not exceeding one mile apart, permanent monuments easily ascertainable. The width of the land located shall not exceed 6 rods, with necessary additions for excavations and embankments, unless the corporation has special legislative authority to make it wider.