There are an estimated 28,000 mule deer in the upper Green River Basin (i.e., Sublette
Herd, Wyoming Game and Fish Department [WGFD] 2006), most of which annually migrate 40
to 100 miles to summer in portions of 5 mountain ranges (Sawyer et al. 2005). Accordingly,
successful management of this deer herd will require that functional migration routes remain
intact. Given the increased levels of both energy (Bureau of Land Management [BLM] 2005) and
housing (Taylor and Lieske 2002) development in Sublette County, identifying and conserving
migration routes has become increasingly important. Currently, migration routes are depicted
by simply connecting the dots between locations of marked animals (e.g., Sawyer et al. 2005,
Berger et al. 2006, White et al. 2007). However, because a line has no area associated with it
(i.e., is it 10 feet or 1 mile wide?), the management value of this approach is limited and can be
especially difficult to incorporate into planning documents (e.g., National Environmental Policy
Act, Resource Management Plans, etc.) or on‐the‐ground management prescriptions (e.g.,
water development, prescribed burns, sagebrush treatments). Further, without specific
knowledge of the relative amounts of use (high, medium, low) migration routes receive, it is
difficult to prioritize specific segments for conservation or enhancement.
