For the first time in seven decades, the Wichita Mountains Wildlife Refuge added three new male bison to its herd.

The three new bison came from Colorado, and according to biologist Dan McDonald, they will add a new genetic code to the herd that will benefit later generations, telling KSWO,

It’s significant for the refuge and it’s also significant for the genetic conservation of this herd and also other bison herds within the fish and wildlife service.

They are younger bulls, each three years old. And so it’ll be a few years before they’re able to breed and make genetic contributions to our herd.

It’s totally new genetics that we were able to add to our herd, supplement the genetics and boost the genetic diversity.

Bison have been part of the refuge for 111 years now, with the original 15 coming from a refuge in the Bronx. These three new bison mark the first new bison additions since some were brought in from Nebraska in the mid-40s.