Washington Chapter | Foundation for North American Wild Sheep ( FNAWS )

Asotin Creek Herd

Population Status and Trend Analysis
Bighorn sheep were reintroduced into the Asotin Creek drainage in 1991 with the release of six bighorn sheep from the Hall Mountain herd in northeast Washington. Another supplemental release occurred in 1994 with the release of nine bighorn sheep from Hall Mountain. The population fluctuated between 10 and 15 bighorn sheep, but failed to show significant growth, probably due to low lamb survival.

A supplemental release of ten bighorn sheep from British Columbia occurred in December of 1997: 2 yearling rams, 7 ewes, and 1 female lamb. If lamb survival improves, this bighorn population should start to show an increasing trend over the next few years.

All of the bighorn sheep form the 1997 release were radio-collared except the lamb, in order to monitor movements. The ewes have confined their movements to the Asotin Creek herd range. The rams have ranged considerable distances and have been monitored in Wenatchee Creek, within the boundaries of the Mt. View herd range. This type of movement will expose the Asotin Creek herd to scabies and other diseases associated with the Mt. View herd.

Habitat Condition and Trend
Habitat conditions within the range of the Asotin Creek herd are generally good. However, yellow-star thistle is invading the area and could cause significant habitat degradation if it is not controlled.

Augmentation/Habitat Enhancement
Weed control projects are being implemented within the herd range. Controlled burns are also in progress on an experimental basis to halt the expansion of yellow-star thistle. Aerial application of herbicides is also being used to control the spread of noxious weeds.

Disease and Parasites
The Asotin Creek herd was not impacted by the Pasteurella die-off that occurred in 1995-96. This herd has remained scabies free since re-introduction, but rams moving between the Asotin and Mt. View herds will, undoubtedly, infect this population with scabies in the near future.

Management Conclusions
The management objective for the Asotin Creek herd is to increase the population to approximately 75-100 bighorn sheep. At that point, the population and habitat will be assessed to determine if the population can expand safely, or herd growth should be controlled. If herd growth needs to be controlled, options for controlling the population will be evaluated: trap and transplant, ewe seasons, etc.

Asotin Creek Rams	Asotin Creek, 1997	Asotin Creek, 1997