Rocky Mountain Bighorn Sheep
Bighorn sheep often receive additional attention because they are a valued game species. The USFS provides substantial habitat for them, and their populations have been growing in North America for the last few decades. The USFS, as part of it’s multiple-use mandate, also permits livestock grazing on National Forest System lands. Conflicts can occur, however, if domestic sheep carrying pathogens, such as disease-causing bacteria, intermix with bighorn sheep. If disease occurs, it may drastically reduce the numbers of bighorn in a herd. The Western Association of Fish and Wildlife Agencies recommends maintaining separation between bighorn and domestic sheep, and the USFS continuously balances its mission to support both healthy wildlife populations and public lands grazing.
Bighorn Sheep Risk of Contact Model
The USFS and Bureau of Land Management supported the development of a tool that can assist the agencies in evaluating the effective spatial separation between a grazing allotment and a bighorn sheep herd. If sufficient data are available, the model can be used to produce a bighorn sheep home-range (the area where the sheep spend most of their time) and estimate the likelihood of bighorn to wander away from their home-range and onto an allotment. Along with behavioral, topological, husbandry, and other information, the model output can be used as part of an analysis to assess the risk of contact, and potential for pathogen transmission between domestic and bighorn sheep.
Map
This web-based mapping tool is designed to give managers a landscape view of bighorn sheep range and USFS domestic sheep grazing allotments. It uses the most up to date and accurate information available but is not necessarily appropriate at the small scale. Details for any particular bighorn herd or livestock grazing allotment would need to be confirmed with the local USFS planning unit and the state fish and wildlife agency.
Policy Information
Chief’s Letters (2011-2014)
- Bighorn Sheep Analysis for NEPA Documents 2011
- Bighorn Sheep Analysis for NEPA Documents 2012
- Bighorn Sheep Analysis for NEPA Documents 2014
WAFWA Recommendations (2012)