Between 1880 and 1932, the Orient Mine in south central Colorado was the largest iron ore producer in the state. At its peak, the mine had two associated town sites with a total population of 400 people. Today, the mine’s seasonal bat residents far surpass the historical records of human dwellers in the area.

The sweeping open landscape in the San Luis Valley allows bat-watchers to keep clear of the mine’s entrance. Photo courtesy of Uncover Colorado.
Mexican free-tailed bats. Bat Conservation International.

An estimated quarter-million Brazilian free-tailed bats (Tadarida brasiliensis) migrate to the Orient Mine each year in warm weather months to rise from the mine’s entrance each evening to sweep over the majestic San Luis Valley and feast on bountiful insects. 

Until recent years, bat viewers stood near a fence at one of the entrances to the mine to watch the bats exit into the night. Proximity to the mine is not recommended at this time. Colorado Parks and Wildlife have closed the mine due to the threats of White-nose syndrome, a debilitating fungus that causes bats to rouse from hibernation and expend necessary body fat during winter months when insect prey is unavailable. White-nose syndrome has resulted in the deaths of millions of North American bat species over a decade and continues to decimate bat colonies. It is not transmissible to humans but humans can transmit the fungus to bats.

The San Luis Valley region is known for its vast views. Find a spot at dusk, from a distance, to watch the bats ascend like a fluttering ribbon into the night sky.


  • In the vicinity of the Orient Mine, Great Sand Dunes National Park offers towers of explorable sand dunes, some as tall as 750 feet high, set against a backdrop of rugged 14,000-foot peaks in Sangre de Cristo mountains. The national park and preserve have been recognized by the International Dark Sky Association as a “Dark Sky Park.” 
  • In addition to migratory Brazilian free-tailed bats, there are 18 bat species within the state of Colorado. Brazilian free-tailed bats are also known as Mexican free-tailed bats.
  • Email Colorado Parks and Wildlife to check on the status of the mine. The state agency asks for 48 hours to respond.
  • The Orient Land Trust – which works in partnership with federal and state agencies as well as conservation organizations to protect natural resources in the area – may also be a good source for information on visiting the area. 
  • The Orient Trust offers high-elevation, rustic accommodations in relative proximity to the mine. Note, that there are no nearby gas stations, restaurants, pharmacies, grocery, or general stores. All properties, including the Trust’s trails and ponds, are clothing optional.
  • In the broader area,  a free visitor guide provides recommendations on accommodations, restaurants, and additional places to see in the region.