Under Alternative A, management objectives in the Red Gulch Dinosaur Tracksite ACEC strive to protect and maintain the paleontological resources, including the largest dinosaur tracksite in Wyoming and other Middle Jurassic fossil deposits.
Surface-disturbing activities are prohibited in the ACEC, except for the construction of roads, trails, interpretive signs, and other facilities to enhance public education and recreation and activities allowed under a paleontological resources use permit.
Prohibiting or restricting surface-disturbing activities in the ACEC would result in adverse impacts to ROWs, renewable energy, and other types of development. Restrictions on surface-disturbing activities would benefit the paleontological value of concern for the ACEC by reducing the potential for destruction or degradation of paleontological resources and values. Under Alternative A, restrictions on mineral development would result in adverse impacts to the use of these resources in the ACEC. Under Alternative A, withdrawing the Red Gulch Dinosaur Tracksite ACEC from appropriation under the mining laws and managing it as open to mineral leasing with an NSO restriction in the Sundance Formation would result in adverse impacts to mineral resources. Withdrawing the ACEC would cause adverse impacts to locatable mineral development in the ACEC by prohibiting extraction of these minerals, particularly where the potential for gypsum is high. Withdrawal would eliminate the potential to develop this mineral because no new claims could be staked; valid existing mining claims represent valid existing rights and would not be affected by the withdrawal (see Section 4.2.1 Locatable Minerals). The development potential for oil and gas in the ACEC is very low and impacts from the restrictions on mineral leasing would be limited. Due to the low potential for sand and gravel across the entire ACEC, impacts to mineral materials disposal from restricting surface-disturbing activities in the ACEC would be limited. Withdrawals and closures to mineral development in the Red Gulch Dinosaur Tracksite ACEC would reduce the potential for destruction or degradation of paleontological values, resulting in beneficial impacts.
Management actions restricting travel and setting permitting requirements would result in adverse impacts to these resource uses by limiting these activities in the ACEC. Restrictions on these resource uses would result in additional protection of and benefits to the paleontological values of concern in the ACEC. Limiting motorized vehicle use to designated roads and trails would restrict access in the area by limiting the roads available for travel. Motorized vehicle restrictions may benefit paleontological resources by reducing the potential for vehicle-caused damage to near-surface paleontological resources, such as dinosaur tracks. All scientific and educational researchers studying the dinosaur tracks or working in that geologic horizon in the Red Gulch Dinosaur Tracksite ACEC are required to obtain a paleontological resources use permit. Permit requirements would protect the integrity of the resources and enable the advancement of scientific knowledge by allowing excavations to continue.
Closing the interpretive area of the Red Gulch Dinosaur Tracksite ACEC to livestock grazing would not affect AUMs, but may provide additional protection for near surface paleontological resources that may be damaged by the passage of livestock.
Prohibiting the use of heavy equipment and chemical and dye retardants may adversely affect the ability to control wildland fires in the area. Reducing surface disturbance and the application of chemicals that may damage exposed dinosaur tracks would be beneficial to the protection of these resources. However, reducing available suppression tactics for wildland fire may increase its area and severity, which may damage paleontological resources close to the surface.
The management of and impacts from the Red Gulch Dinosaur Tracksite ACEC under Alternative B are the same as under Alternative A.
Under Alternative C, the BLM would not manage the Red Gulch Dinosaur Tracksite area as an ACEC, but would manage it in accordance with multiple use principles consistent with other resource objectives.
Under Alternative C, the area is open to locatable mineral entry, mineral leasing, and mineral materials disposal. There would be moderate constraints on oil and gas development in a portion of the area (1,674 acres), and the remainder of the area would be open to mineral leasing subject to standard lease stipulations. Alternative C includes the fewest restrictions on mineral development and would result in the smallest impact on the development of these resources. This management would result in the greatest adverse impacts to the paleontological values of concern compared to the other alternatives.
Managing the area under Alternative C would result in more surface disturbance that alternatives A and B. Under Alternative C, the BLM would manage the Red Gulch Dinosaur Tracksite area primarily as an ROW avoidance/mitigation area (1,674 acres) or open to ROW authorizations, although standard guidelines for surface disturbance would apply. Alternative C would allow for more potential ROW development in the area compared to the other alternatives, which would result in the greatest potential for damage to near-surface paleontological resources.
Alternative C limits motorized vehicle use to designated roads and trails; impacts from travel would be the same as under alternatives A and B.
Applicable laws and regulations and the management described in Section 4.5.2 Paleontological Resources control the collection of fossils under Alternative C. These decisions include protective management, such as surveying and monitoring requirements in PFYC 5 formations, but generally would provide less protection for the paleontological values of concern than the other alternatives.
The management of and impacts from the Red Gulch Dinosaur Tracksite ACEC under Alternative D are the same as under Alternative A.
Under alternatives A, B, and D, the BLM would designate the Sheep Mountain Anticline area an ACEC (11,528 acres), and would not designate it as an ACEC under Alternative C. The values of concern in the Sheep Mountain Anticline ACEC are geologic features, caves, cultural resources, and scenic qualities. The primary feature of the area is its classic Laramide anticline. Threats to the resource values in this area include surface disturbance from mineral and ROW development.