The park
Custer State Park covers approximately 290 square kilometres in the southern Black Hills of South Dakota, immediately north of Wind Cave National Park and south of Mount Rushmore. The park was established by the state of South Dakota in 1912 and is the largest state park in the United States by area. Its terrain ranges from open grasslands on the southern and eastern sides to dense ponderosa pine forest on the northern and western sides, with substantial granite outcrops including the famous Needles Highway formations.
The park's wildlife management programme includes bison, elk, bighorn sheep, pronghorn, mountain goats, mule deer, white-tailed deer, the begging burros (descendants of pack animals released after Cold War-era mining operations), and a substantial bird community. The park is the centrepiece of South Dakota's wildlife tourism economy and one of the most visited state parks in the country.
The founder history
The Custer State Park bison herd was founded in 1914 by the purchase of thirty-six animals from the herd of rancher James "Scotty" Philip of Fort Pierre, South Dakota. Scotty Philip's herd was itself descended from animals captured by his Lakota brother-in-law Pete Dupree in the early 1880s, in the final years of the wild Plains population. Pete Dupree's capture of five bison calves from a wild herd in western South Dakota produced one of the small number of surviving bloodlines that avoided the worst of the commercial hunt collapse.
The Dupree-Philip lineage is one of the more direct connections between the late-19th-century wild Plains population and any modern conservation herd. The Custer State Park herd, the South Dakota State Game Park herd that later merged with Custer's, and several private South Dakota herds all trace ancestry to the Dupree-Philip line. The historical depth of the connection makes the Custer herd culturally significant beyond its current management role.
The herd grew steadily through the 20th century from the original 36 founders. By the 1940s the population had grown into the hundreds and the park began the round-up and auction system that has been refined into its modern form. The annual round-up has been a continuous event for more than 50 years, with the modern public viewing element added in the 1980s.
The annual round-up
The Custer State Park Buffalo Round-Up takes place on the last Friday of September each year. The event has become one of the largest public bison events in North America and draws crowds of more than 20,000 visitors to designated viewing areas along the round-up route. The round-up itself is a serious working operation: the entire herd of approximately 1,400 animals is gathered from the park's grazing range and driven into the permanent corral system on the southern side of the park.
The drive uses approximately 50 to 60 mounted riders (some park staff, many volunteer cowboys and ranch hands invited annually) plus support vehicles. The herd is gathered from across multiple sub-areas of the park and pushed through a corridor that the viewing public watches from designated raised viewing areas. The drive typically takes two to three hours from the start to the herd's arrival at the corrals.
Once at the corrals, the herd is held overnight and then processed across the following week. Each animal is individually evaluated: weight, body condition, age, and sex are recorded; health testing is performed (the Custer herd has been historically brucellosis-free and the testing confirms continuing status); vaccinations are administered to calves and yearlings; surplus animals are identified for the auction.
The Buffalo Round-Up has been recognised by the South Dakota Department of Tourism as one of the state's signature events. Hotels and campgrounds in Custer and Rapid City fill months in advance. The associated Buffalo Round-Up Arts Festival, held in the park's headquarters area through the round-up weekend, features Western art, music, and craft vendors and adds to the visitor draw.
The bison auction
Following the round-up, Custer State Park holds a public bison auction. The animals offered are those identified by park staff as surplus to the management target. The auction is open to qualified buyers, including commercial bison ranchers, smaller conservation operations, Tribal organisations, and the InterTribal Buffalo Council network. The auction is one of the most significant public bison sales in the United States by volume and is a substantial revenue source for the park's wildlife management programme.
The auction is run on a competitive bidding basis with reserve prices set by park management. Animals are typically sorted into sale lots by age, sex, and breeding potential, with breeding bulls and cows priced separately from animals destined for commercial meat production. The transfer to InterTribal Buffalo Council recipients has expanded substantially in recent years, with a portion of the herd routed specifically to Tribal restoration programmes outside the open auction process.
The Wildlife Loop and visitor viewing
The Wildlife Loop Road is an 18-mile (29 km) paved drive through the southern and eastern parts of Custer State Park, looping through the open grasslands where the bison herd most frequently grazes. The road is the primary visitor wildlife experience and reliably produces bison sightings throughout the year. Visitors should expect to encounter bison on or near the road and to slow or stop while the animals cross or move alongside.
Early morning and late afternoon produce the best wildlife light and the highest activity levels. The road is open to private vehicles year-round, with winter access subject to snow and ice conditions. The drive takes approximately one hour without stops; visitors who want to spend time photographing or simply watching bison should allow two to four hours. The Wildlife Loop is one of the more accessible large-mammal viewing experiences in the United States and is consistently ranked among the best wildlife drives in the country by travel publications.
Beyond the bison, the Wildlife Loop reliably produces sightings of pronghorn, mule deer, prairie dogs, and the begging burros that line up alongside the road in certain sections expecting handouts from visitors. Bighorn sheep are present in the granite areas of the Needles Highway in the northern part of the park.
The herd's conservation role
Custer State Park's herd is a working conservation population rather than a strict preservation herd. The auction system removes a portion of the herd annually, channeling animals into a mix of conservation and commercial destinations. The volume of animals moved through the auction over the past several decades has been substantial and Custer-sourced bison contribute to many of the smaller conservation herds and to a significant fraction of the commercial bison ranching network in the central and northern Plains.
The herd's genetic profile is less restricted than the strict introgression-free herds at Wind Cave, Yellowstone, and Henry Mountains. Custer State Park animals carry low-level cattle gene introgression typical of many conservation bison populations, reflecting the open auction and exchange history of the herd throughout the 20th century. The introgression does not affect the animals' wild phenotype or behaviour in any visible way but limits the herd's suitability as a strict-genetic-preservation source. For conservation transfers prioritising introgression-free animals, Wind Cave is the more commonly used source. For general bison restoration and for commercial breeding, Custer is one of the most useful sources in the country.
Custer in the Black Hills context
Custer State Park sits at the centre of the Black Hills bison cluster. The neighbouring units include Wind Cave National Park (covered in detail on the Wind Cave bison page), Mount Rushmore and the surrounding Black Hills National Forest, and the Black Hills Wild Horse Sanctuary. A typical visitor itinerary combines Custer State Park (bison and wildlife drive), Wind Cave (cave tour plus bison viewing), Mount Rushmore (the monument), and the Needles Highway (the granite formations within Custer State Park). The combined Black Hills bison experience spans two major herds (Custer and Wind Cave) totalling roughly 1,800 animals across a contiguous protected landscape.
Frequently asked questions
What does the round-up cost to attend?
The round-up itself is free to attend, but the park's standard vehicle entry fee applies. Some viewing areas have parking limits and arrive-early requirements because of the crowd size. The South Dakota Department of Tourism publishes annual logistics guidance ahead of the event.
How is the round-up safer than it looks?
The mounted riders are experienced ranch and rodeo hands, the route is well scouted, and the herd is acclimated to the annual event after decades of repetition. The bison push without serious resistance most years. Injuries to riders or animals are rare but not zero; the round-up is a working operation rather than a staged spectacle.
Why does Custer have such a large herd compared to Wind Cave?
More acreage and less restrictive genetic management. Custer's 290 sq km support roughly four times the bison population of Wind Cave's 137 sq km. The genetic cleanliness priority that limits Wind Cave's growth and shapes its management does not apply equally to Custer.
Can visitors get out of vehicles around bison?
Not safely. South Dakota Game, Fish and Parks rules echo the National Park Service 25-yard minimum distance recommendation, and visitors should stay in or close to their vehicles when bison are near the road. Bison-related visitor injuries occur at Custer State Park each year, almost always from visitors who approached for photographs.