Gateway West and Chokecherry: Informing Wildlife-Friendly Energy Development in the West

2GatewayWestMapHawkWatch International's Conservation Science Director, Dr. Steve Slater, recently submitted public comment on Environmental Impact Statements (EIS) of two energy developments being planned in the western U.S.

First is Gateway West, an energy transmission line proposed to span across Wyoming and southern Idaho, totalling construction of approximately 1,100 miles of 230 kilovolt (kV) and 500kV power lines.

The following summarizes some of HawkWatch International's primary concerns regarding the development, as well as suggestions to emeliorate them:

  1. We encourage the adoption of the single solid pole-structures for the transmission line towers to the maximum extent possible in order to avoid supporting increases in common raven populations. Ravens are known predators of greater sage-grouse. Sage-grouse were petitioned for listing in 2010 and remain on the candidate list and raven depredation may become a concern for population stabilization or recovery.
  2. Power line structures without perch deterrents installed may also unnaturally concentrate raptors to the potential detriment of prey species such as: sage-grouse, pygmy rabbits, white-tailed prairie dog, ferruginous hawk, burrowing owl, sage thrasher, loggerhead shrike, Brewer’s sparrow, and sage sparrow.
  3. It is critical that raptor nest surveys and protection measures are adhered to during construction and operation activities to avoid take of nests or disruption of breeding activity.
  4. Transmission lines and associated structures can also be dangerous for birds due to risk of electrocution or collision.  Regarding electrocution, we suggest that an Avian Protection Plan be developed for the transmission line in accordance with APLIC guidelines (
  5. Unfortunately, the EIS does not give adequate consideration to the raptor collision risk associated with the project proponent’s preferred route that transects a known raptor migration ridgeline.  HawkWatch International has operated a fall migration count on Commissary Ridge for the past 10 years and has recorded an average passage of 3,665 raptors each fall and an average of 400 eagles. Both Bald and Golden Eagles are protected by the Migratory Bird Treaty Act and the Bald and Golden Eagle protection Act.  The Bald Eagle is also a Wyoming BLM sensitive species.

Read Dr. Slater's full comment on the Gateway West Transmission Line: HawkWatch_GWDEIS_Comments.pdf 

Send your own comments to by October 28th. 



Second is the Chokecherry & Sierra Madre Wind Energy Project. The Power Company of Wyoming (PCW) has applied to the BLM for a right-of-way to build approximately 1,000 wind turbines south of Rawlins, Wyoming. Chokecherry and Sierra Madre are two distinct sites approximately five miles apart. The project is expected to generate between 2,000 to 3,000 megawatts (MW) of electricity. Along with the turbines, the project also proposes building access roads, underground electric gathering lines, an overhead transmission line, and substations
to interconnect the generated power to the electric grid. HawkWatch International recognizes the need for alternative forms of energy development and energy conservation to reduce our dependency on fossil fuels. However, all development projects pose a risk to wildlife and must be carefully designed and sited to reduce this risk to the degree possible.

The following summarizes some of HawkWatch International's primary concerns and recommendations regarding the Draft Environmental Impact Statement (DEIS) prepared by the BLM for this proposed wind project:

1. Given the raptor data collected by BLM and cited in the DEIS, we cannot agree with the BLM’s conclusion that this project will have “no cumulative impact through population reductions for raptors” without substantial additional support for this claim.

2. We do not have confidence in the raptor and eagle mortality estimates provided in the DEIS due to flaws in the proposed relationship between pre-survey raptor activity and mortality risk and the high level of uncertainty in the provided estimate. Although the report suggests an annual mortality of 120 raptors, the high uncertainty in the estimate produces a 90% prediction interval of 0-900 birds. Additionally, an alternate model of mortality risk suggests an annual mortality of 708 raptors and 215 Golden Eagles, compared to the DEIS estimates of 120 raptors and 36 eagles. Even at the lowest estimate of annual eagle mortality (36) there is concern that this level of mortality could have a cumulative impacts on the local population.

3. We find that too little attention is given to potential mitigation or management considerations to reduce risk to raptors. At a minimum, the Rawlins BLM’s “key raptor areas” and extensive knowledge of raptor nesting concentrations gathered over a 30-
year period should be used to guide where development may or may not be allowed.  In particular, development should avoid the Atlantic Rim area and the cliffs along the southern boundary of the Chokecherry project area to avoid potential impacts in high
value raptor habitat.

4. We also suggest that the BLM use a larger buffer around the high value raptor areas than the 1-mile buffer BLM currently used for Golden Eagles. The current BLM spatial buffer was designed to prevent disturbance to nesting birds (e.g., from oil and gas drilling); they were not intended to protect birds hunting around their nests from potential interaction
with turbines.

Read Dr. Slater's full comment here: Chokecherry Comments 

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