The Bureau of Land Management (BLM) is currently revising a Resource Management Plan (RMP) that will shape management of the Pinedale Resource Management Area (RMA), in western Wyoming, over the next 15 to 20 years. The Pinedale RMA includes the Upper Green River Valley, winter habitat for over 100,000 pronghorn, mule deer, elk, bighorn sheep, moose, and other big game. The valley also contains winter habitat and mating, nesting, and brood-rearing areas favored by Greater Sage-Grouse, one of the West’s signature game birds and a species whose future is far from certain.
In its RMP revision, the BLM faces the delicate task of balancing the needs of the world-class wildlife populations of the Upper Green River Valley with development of some of the nation’s most productive onshore natural gas fields, which occur in the same area. Scientific studies have shown that the infrastructure of natural gas development -- wells, drill pads, roads, pipelines, and other features -- can harm wildlife populations, displacing them from preferred areas, making them more vulnerable to predation, and reducing the effectiveness of habitat for forage, breeding, or other life functions. While the direct effects of oil and gas drilling may be limited to the physical footprint of roads and well pads, the complex web of these structures across the landscape causes indirect and cumulative effects on habitat quality and connectivity that extend well beyond the physical structures and can last long after gas extraction is completed.
In this report, we present a spatial analysis of the existing transportation network in a 2.9-million-acre area of the Pinedale RMA where both the crucial habitat for big game and Sage-Grouse and the area’s largest natural gas fields are concentrated. This analysis, which uses Geographic Information System (GIS) route datasets provided by the BLM, reveals that the Upper Green River Valley’s crucial habitat is already severely fragmented by transportation routes. Findings suggest that the current level of development is sufficient to have a negative impact on the four wildlife species assessed -- pronghorn, mule deer, elk, and Sage-Grouse. Key findings include:
- The lower-elevation lands in the Pinedale RMA that are most important for wintering big game and wintering and breeding Sage-Grouse have the highest route densities, smallest core areas, and shortest average distance-to-route values in the study area.
- The current transportation network is most extensive within the oil and gas fields, particularly the Jonah Field, which is the most heavily developed field with 95 percent of its area having route densities greater than 2 mi/mi2.
- Eighty percent of pronghorn crucial winter range has route densities higher than 1 mi/mi2, which is suggested by the BLM to adversely affect this species.
- Sixty-six percent of elk crucial winter habitat has route densities greater than 1 mi/mi2, a level of development that has been suggested to severely restrict elk habitat in open landscapes.
- All Greater Sage-Grouse leks (courtship/mating areas) in the study are within 3 miles of a road, the distance from surface disturbance recommended for seasonal closures to preserve breeding functions.
Given the rapid recent development of new roads and infrastructure for oil and gas development in the Upper Green River Valley, and the likelihood that the transportation network will increase as development proceeds in the coming years, the BLM is now at a critical juncture in deciding the long-term fate of key habitat for the nationally significant wildlife populations found there. We urge the BLM to adopt, through its upcoming RMP revision, a responsible transportation plan that will improve the Pinedale RMA’s long-term ecological health and integrity while providing for balanced public access and use of the landscape and its resources.
The analysis used to create this report and the results generated can and should be used by the BLM to make sound, science-based decisions in revising the Pinedale RMP, in designating or limiting areas for further development, and in determining those areas where roads should be closed or subject to limited use. A number of specific recommendations are derived from the spatial analysis conducted in the present study:
- Develop and implement route closure and reclamation plans to restore and maintain critical big-game habitat and habitat linkages:
- Mule deer: Increase the amount of core area greater than 1,542 feet from a route within crucial winter range and along migration corridors.
- Pronghorn: Increase the amount of core area greater than 3,168 feet from a route and reduce route densities below 1 mi/mi2 within crucial winter range and along migration corridors.
- Elk: Reduce route densities below 1 mi/mi2 within crucial winter range and along migration corridors.
- Prohibit drilling and surface occupancy in big-game wintering areas between November 15th and April 30th.
- Implement seasonal traffic restrictions on all roads within 656 feet of Sage-Grouse winter habitat (9:00 am to 5:30 pm, mid-November through March), within 3 miles of breeding and nesting areas (9:00 am to 5:30 pm, March through mid-May), and in brood-rearing areas (9:00 am to 5:30 pm, June through mid-July). Impose a speed limit of 30 miles per hour during non-restricted hours.
These species-specific recommendations should be combined with more general provisions to benefit all wildlife species in the area, such as requiring directional drilling and cluster development; planning for staged development of energy resources; restricting new roads and energy development; allowing few exceptions to temporal occupancy restrictions; designating Areas of Critical Environmental Concern (ACECs); imposing rigorous standards for ecological restoration of closed routes; and continuing to research the effects of the transportation network on wildlife species and using this knowledge in adaptive management. Profitable natural gas extraction and healthy wildlife populations can coexist in the Pinedale RMA, but only if the BLM adopts measures to close and reclaim unnecessary transportation routes and regulate the remaining ones to minimize their impacts on wildlife.