The Environment

The Wild Horses and their Environment

Anyone who travels through the Yakama Nation Reservation on highway US 97 between Goldendale, WA and Toppenish is likely to see small bands of wild horses grazing on hillsides on either side of the highway.  These are but a few of the several thousands of free roaming horses that live out of sight in the reservation’s hills and canyons.

The Land

Over the past few years, newspapers and magazines throughout the state have published numerous articles about wild horses on the Yakama Reservation. Many of these articles discuss the impacts that high horse population are having on the land, streams and other wildlife within the reservation and the efforts by the Yakama Nation to ameliorate these impacts. To better understand these problems and their causes, it is useful to know a little about the geographic environment in which the horses live. This section will look at some of the ecological factors that contribute to the problem

The Yakama Reservation is divided into three horse management areas (HMA) of roughly equal size: East Satus HMA, located east of US highway 97, West Satus HMA, located west of the highway, and Ahtanum/Toppenish HMA located along the western side of the reservation.

Both East and West Satus areas consist mostly of shrub-steppe rangeland with some heavily harvested forests at the edges. The Ahtanum/Toppenish area contains more forested land. While there are many horses in each of the three areas, West Satus contains the highest population, and their impacts are greatest here. Consequently, most of my observations for more than a decade were made in this area. 

Toppenish Ridge forms the northern boundary of the West Satus HMA. The ridge is treeless and has very little sagebrush due to many fires

Horses grazing on the ridge can see for miles in all directions.

To the west the shrub-steppe vegetation gradually transforms into forests and the foothills of Mt. Adams
Among the trees, horses are difficult to find.
The southern border of West Satus runs along the base of the Simcoe Mountains
Here, much of the land is flat and covered with sagebrush.
Land parallel to Highway 97 on the east is mostly open rangeland, with a few low hills covered with sagebrush and steep canyons.
Two steep, rocky canyons run west to east through the middle of West Satus HMA: Dry Creek Canyon and Logy Creek canyon.
Although these canyons are quite steep, many of the horses appear comfortable grazing and climbing the rocky walls

The Seasons

As soon as the snow disappears in early spring, the land is already green. Cheatgrass, an annual plant, is the predominant grass throughout much of the reservation, the result of overgrazing over the decades. Cheatgrass begins to germinate in November/December, even under a blanket of snow, and continues to grow throughout much of the winter. By spring the land is covered with succulent Cheatgrass.

Cheatgrass is followed quickly by a series of spring wildflowers:

Bitterroot
Yellow Bell
Cushion Daisy
Sagebrush Violet

By midsummer all the spring flowers are dead. The omnipresent cheatgrass has flowered, produced seeds and died leaving the land covered with a tan carpet of dry leaves and stems.

From summer until snowfall, the horses continue to browse the dry, dead grass

When winter begins and snow covers the ground at higher elevations, the horses move to the lower elevations.

Where they find forage in the riparian areas along the many streams and creeks.

In 2007, a comprehensive plan to manage the reservation lands for the benefit of all grazing animals was developed by the Yakama Nation Wildlife, Range and Vegetation Management Program. This plan recommended that wild horse numbers be adjusted to a total of 1000 across all three horse management areas, with 500 scheduled for the West Satus area. Unfortunately, this goal has never been reached. The impacts that the excess numbers of horses are having on the land are presented in another section.