Turner Bison Exchange

Castle Rock Herd

Description: Castle Rock Herd

The Turner Ranches Castle Rock bison herd get their name from the unique geologic feature at Castle Rock Park on the 550,000-acre Vermejo Park Ranch in northern New Mexico.  At 8200 feet elevation, this area of Vermejo was “home” to these bison since the 1920’s.  They have survived this harsh high elevation environment with no supplementation for nearly a century while remaining sound and reproductively efficient.  The Turner Ranches Castle Rock bison herd has Yellowstone origins with additional diversity of pure bison genetics (animals with no sign of cattle introgression) from three other foundation herds.

The original animals of the Castle Rock bison herd were transplanted to Vermejo Park Ranch with elk from Yellowstone National Park between 1920 and 1940.   In the 1950’s, thirteen bison from Philmont Scout Ranch were released with the Castle Rock bison.  The Philmont herd was originally founded from bison purchased from Yellowstone in the early 1920’s.  In the 1980’s, six bulls from the foundational Maxwell herd in Kansas were introduced to the herd.  Since that time, the Castle Rock herd has been closed to outside genetics.

The Castle Rock bison became perfectly-adapted to their high mountain and canyon environment, thriving without intervention through periods of variable precipitation and forage production.  During 2015 and 2016, 30 Castle Rock bulls and 560 Castle Rock females were moved to the Snowcrest Ranch in southwest Montana, where they run in high, cold, and diverse country from river bottoms, through intermediate hills, to forested mountain country. 

The Castle Rock herd have most of the unique alleles present in Yellowstone National Park bison.  Genetic analysis by Texas A&M University (2010) determined Castle Rock bison share 99 alleles with Yellowstone bison, yet also maintain 16 unique alleles.  Upon comparing Castle Rock bison with 11 Department of Interior herds, Castle Rock genetics cluster also with Wichita Mountains National Wildlife Refuge (OK), Wind Cave National Park (SD), Fort Niobrara National Wildlife Refuge (NE), and the National Bison Range (MT).  Extensive genetic testing from Texas A&M University have found no sign of cattle introgression DNA present in the herd.

The Castle Rock bison have been proven unique both historically and genetically.   These animals hold a large portion of the genes (they have genes from four of the six foundation herds) that originated from North American bison before European settlement of the West (pre-1850) making them one of the few privately held “foundation genetic” herds.