Colorado Wild Horse Herds
Colorado has four HMAs: Sand Springs Basin, Sand Wash, East Douglas/Pieceance, and Little BookCliffs. They are located West of the Rockies, in the Great Basin. They are a mix of short-grass prairie and high desert ecological communities. All four Herds have organized citizen groups who monitor, photograph, document, and advocate for them, and - in some cases - participate in PZP fertility control efforts.