N.H. Rev. Stat. Ann. § 246:24

In the case of a private crossing, such order shall be served upon the railroad and the landowner affected, or his legal representative. In the case of public crossings, service shall be made upon the railroad, the clerk or clerks of the towns directly served by such crossing, and, in addition, the order shall be published in a newspaper having general circulation throughout the county where such crossing is located.