The Turner Castle Rock bison herd

Yellowstone origins with a diversity of Foundation bison genetics.

Turner Enterprises acquired the Castle Rock bison herd in 1996, with the purchase of the 560,000-acre Vermejo Park Ranch in northern New Mexico.  The herd takes its name from the aptly-named geologic feature on the ranch, situated in an intermountain park over 8,000’ elevation.

Photo: Castle Rock Park Landscape at Vermejo Park Ranch.

Photo Link: https://photos.app.goo.gl/pztqKG9qw13yfCyq7

The foundation animals of the Castle Rock bison herd are believed to have been transplanted to Vermejo Park Ranch along 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, 6 bulls from the foundational Maxwell herd in Kansas were introduced to the herd.  Since that time, the Castle Rock herd has been closed.  Over many generations without human intervention, the Castle Rock bison became well-adapted to their high-elevation, mountain and canyon environment, thriving through periods of variable precipitation and forage production. 

To increase the Castle Rock herds’ genetic reservoir and expand its geographic range, in 2015 and 2016, 30 Castle Rock bulls and 180 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 transitional hills and basins to forested mountain country.  Turner Enterprises has offered animals from the Castle Rock herds at both Vermejo Park and Snowcrest Ranch in the annual Turner Ranches Prairie Production Auction.

In 2010, Texas A&M University completed a Conservation Genetic Analysis of the Castle Rock Bison (Derr and Marshall, 2010).  The herd was evaluated for evidence of domestic cattle DNA introgression using 14 nuclear microsatellite markers and mitochondrial DNA genotyping.  All animals examined from this herd had bison mitochondrial DNA.  Although the study was limited to 14 nuclear microsatellite markers by the technology of the time, the investigators concluded the overall level of possible introgression in this herd is very small and at the extreme lower detection limit of current technology

Turner Enterprises continues to annually tests any newborn animals to the Castle Rock herd for cattle mitochondrial DNA (mDNA), and no cattle mDNA has been found in the herd.

Additionally, the TAMU study utilized contemporary genetic technologies to determine the level, distribution, and origin of genetic diversity in the Castle Rock herd.  Genetic variation based on the average number of alleles per locus indicate moderate to high diversity levels existing in the herd.  The study concluded the Castle Rock herd retains many of the unique alleles present in Yellowstone National Park bison, sharing 99 alleles with Yellowstone bison, while also maintaining 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).

Link to Figures: https://photos.app.goo.gl/pztqKG9qw13yfCyq7

Figure 1. – Allelic comparison between YNP and CR herd.

Figure 2. – Structure analysis of private herd (CR) with the 11 DOI herds. The DOI herds group into 8 known clusters (Halbert and Derr 2008) labeled above as Badlands National Park (BNP), Fort Niobrara  NWR (FN), National Bison Range (NBR), Theodore Roosevelt National Park North (TNR), Theodore Roosevelt National Park South (TRS), Wind Cave National Park (WC), Wichita Mountain NWR (WM), and Yellowstone National Park (YNP). This figure shows how the private herd relates to the DOI herds within the 8 clusters. It would be expected to cluster with YNP but, as shown, it groups with many different clusters including WM, WC, FN, and NBR.

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 4 of the 6 foundation herds) that originated from North American bison before European settlement of the West (pre-1850).

Citations:

Halbert ND, Derr JN (2008) Patterns of genetic variation in US federal bison herds. Molecular Ecology, 17, 4963-4977

Marshall AS, Derr JN (2010) Conservation Genetic Analysis of the Castle Rock Bison Herd on the Vermejo Park Ranch, Final Project Report, Undergraduate Research Scholar Thesis, Genetics/Biochemistry, 1-20