What Does The DEIS Say About Big Game?

Short Version: No identified mule deer migration routes were mapped in the proposed Project’s corridors, however, pronghorn was identified to have affinity for a migration corridor near the center-west portion of the site during wintering months. MVE has committed to numerous measures to help mitigate any impact to big game. These measures include:

  • minimizing new roads,
  • observing speed limits,
  • implementing a wildlife incident reporting system,
  • minimizing fencing and ensuring fencing follows appropriate guidelines,
  • minimizing construction during the wintering period.

These measures would further minimize the potential winter displacement effects and potential for vehicle collisions to mule deer and pronghorn. When combined with the implementation of applicant-committed measures and other mitigation, the additional reduction in seasonal noise and vegetation disturbance in pronghorn winter habitat would result in greatly reduced impacts of the action alternatives to wintering pronghorn populations.

Detailed Summary:
The DEIS provides a detailed evaluation of the effects of the Project on big game, including mule deer and pronghorn. The DEIS examined the impacts on big game movement, habitat, and population. Development projects can potentially affect big game through temporary habitat disturbance during construction via fencing and human activity. The DEIS reports that the temporary construction would occur in a small portion of the proposed Project Area (Alternative B) at any given time, allowing animals to shift their activity to avoid active construction sites when moving through the analysis area.

The DEIS looked at the most recent scientific information and knowledge of regional subject experts to determine an analysis area and annual range of mule deer and pronghorn populations. No identified mule deer migration routes or stopover areas were mapped in the proposed Project’s corridors. Pronghorn was identified to have some migration near the center-west portion of the site during wintering months, which may contribute to some habitat loss due to ground disturbance. However, the disruption during migratory and stopover habitat for pronghorn is minimal: up to 150 acres during construction and up to only 39 acres after construction for Alternative B (acreages would be even lower for the other alternatives studied).

Temporary fencing used in the Project’s construction phase may impact mule deer and pronghorn; however, MVE has committed to using minimal fencing and fencing that adheres to the appropriate BLM guidelines for fencing. Human noise and activity during construction may result in avoidance of existing migratory routes between winter and summer ranges for mule deer and pronghorn. The DEIS noted that because construction is only approximately two years long, big game will be able to remember and continue to use these routes post-construction.

To help identify potential areas of concern, MVE has created an Environmental Compliance Monitoring Program, which will implement a monitoring system to record incidental animal observations during the life of the Project. This program will help MVE work with agencies on adaptive management strategies to mitigate impacts to big game in the proposed Project area.

Big Game Issues Analyzed in Brief
Many impacts would be below significance due to MVE’s commitment to meaningful mitigation measures. The table below shows the issue analyzed in brief and the result of the analysis:

Preliminary Issue Analysis
How would changes in hunter access via new or improved roads affect big game populations? Though this would increase hunter access in the analysis area, it is unlikely to lead to changes in overall take of big game species.
How would the Project affect wildlife habitat and territory use? Any additional Project-specific disclosure of effects to foraging habitat and/or migratory and territory use for general wildlife would not exceed the level of effects included in BLMs previous policies.
How would the Project affect elk habitat and population distribution? Impact context is so low that detailed analysis is not needed to determine significance.