Mille Lacs National Wildlife Refuge is a tiny federal refuge on two small islands in Mille Lacs Lake in central Minnesota. Covering just 0.57 acre, about 2,300 square meters, it is the smallest National Wildlife Refuge in the United States. Established on May 14, 1915, its significance lies in protecting breeding habitat for birds. The islands are one of only four breeding colonies in Minnesota for the common tern, a state-threatened species, and they also support ring-billed gulls, herring gulls, and double-crested cormorants. Reachable only by boat, the refuge discourages landing and encourages birdwatching from the water to avoid disturbing nesting birds.