Big Diamond Pond is a good Trout fishing pond adjacent to Coleman State Park in Stewartstown, NH. The pond is readily accessible with a state owned launch site on it's southwestern shore. Big Diamond is also open for ice fishing for Lake and Rainbow Trout. The pond provides consistently good fishing during the year, especially in spring and fall. Ice-out occurs during the 2nd week of May. The state’s largest Cusk was caught on Big Diamond Pond.