Excerpt from NHF&G news letter today....
Although vast amounts of open water are already present on most large lakes this mid-March, it is imperative anglers keep in mind landlocked salmon/lake trout managed lakes are closed to all open water fishing until April 1, regardless of the species targeted. Only ice fishing (as ice permits) is allowed from the period January 1-March 31. However, keep in mind numerous general regulation water bodies are open to fishing by all legal methods year-round, as well as, currently, streams/rivers which reopened January 1. (See the N.H. Freshwater Fishing Digest for further information).