Black Tern Bog State Natural Area is a protected wetland in southwestern Vilas County, Wisconsin, covering twenty acres of quaking sphagnum bog around two small seepage lakes in a pitted outwash plain. Its acidic habitat supports specialized plant life, including sundews, pitcher plant, bogbean, bog rosemary, and several bog orchids such as swamp pink, grass pink, and rose pogonia. The state-endangered bog rush also grows here, highlighting the site’s conservation importance. Birdlife further adds to its significance, with black terns nesting here along with American bitterns, killdeer, and mallards.