CAREY, Idaho - Craters of the Moon National Monument and Preserve in south-central Idaho has been designated an International Dark Sky Park due to its exceptional stargazing.

National Park Service officials formally announced the designation Tuesday that the Tucson, Arizona,-based International Dark-Sky Association made last month.

Craters of the Moon spokesman Ted Stout says the monument and preserve is the 21st area in the National Park Service system to receive the designation.

Overall, it's among only 39 sites in the United States to be named an International Dark Sky Park.

Stout says the night-sky viewing is excellent at Craters of the Moon because of its distance from large cities and the low southern horizon looking out over the Snake River Plain.