Wild horses cost American taxpayers $77 million a year. But a man who helps shrink wild horse herds with birth control vaccine hopes to reduce those costs.

A wild horse herd lives on BLM land in the McCullough peaks, just east of Cody. BLM officials used to do gathers here, to reduce the herd size… but it’s not growing anymore, thanks to a contraceptive called PZP 

Senior Scientist of the Science and Conservation Center Jay F. Kirkpatrick said, “They reached zero population growth in three years flat. They’re balancing foal production with mortality.”

The non-profit Science and Conservation Center is in Billings. The center helps public, private, and tribal groups control dozens of wild horse populations around the  world.

Some have concerns though. Powell rancher Tom Hagwood has won national awards for training wild horses. He supports the idea of population control, to avoid starvation.

But, he wonders if darting horses in a small area, like the Pryor Mountains or McCulloug Peaks, is the same as trying to dart them on a huge landscape.

He said, “I just don’t see where they’re going to be able to walk out across that desert and dart those horses. That’s too much area.”

But supporters say studies show it works. PZP is also used to control herds of elephants, deer, and bison.