N.H. Rev. Stat. Ann. § 230:19

The governor and council, or the commission, at the time and place appointed for hearing shall make a personal examination of the proposed location, and of any highway for which the proposed highway is designed to be a substitute, shall hear all parties interested who may attend, and may adjourn as they see cause. They may admit or reject any evidence offered and there shall be no appeal from their findings on the matter of occasion for the laying out of the highway or alteration thereof in the absence of fraud or gross mistake.