Jewel Cave National Monument is a 1,274-acre park in the Black Hills of western South Dakota established to protect the third longest cave in the world. While the main visitor area of the cave does not have bats, an entrance enlarged in the early 1900s is now used as a bat hibernaculum (winter home for bats). Surface water is rare in the park where the majority of habitat is open ponderosa pine forest with grassland meadows, though there is a sewage pond that potentially provides a source of drinking water for bats.
The Northern Great Plains Inventory & Monitoring Network monitors to detect long-trends in bat populations at the park. Four acoustic recording stations were established in 2014–2015 at Jewel Cave National Monument. Acoustic recorders detect the unique ultrasonic calls bats use for echolocation. There were 30,450 bat call recordings from stations across all survey nights from 2014–2015. The data were analyzed through specialized software programs that make preliminary identifications of the bat species based on individual call characteristics, such as frequency and shape. Some bat species make calls that are similar to other species, which is why researchers with special expertise review the calls and make the final species determinations.