Part of the planning process for the Bighorn Basin RMP Revision Project included a review of BLM-administered lands to determine whether they met the criteria for designation as ACECs. The ACEC designation is an administrative designation used by the BLM that is accomplished through the land use planning process. It is unique to the BLM in that no other agency uses this form of designation. The Federal Land Policy and Management Act (FLPMA), states that the BLM will give priority to the designation and protection of ACECs in the development and revision of land use plans.
ACECs are composed of only BLM-administered lands, and private lands and lands administered by other agencies are not included in the boundaries of ACECs. Unlike other special designations, such as wilderness study areas (WSAs), the designation of an area as an ACEC does not by itself automatically prohibit or restrict other uses in the area (with the exception that a mining plan of operation is required for any proposed mining activity within a designated ACEC). However, to be considered for designation, special management beyond the standard provisions established by the RMP must be required to protect relevant and important qualities (described below).
Several steps are required to identify and evaluate ACECs. These steps include (1) the nomination of areas by the public during scoping or by BLM resource specialists, (2) evaluation of the nominated areas to determine if they meet the importance and relevance criteria described below, and (3) consideration of the potential ACECs as management scenarios analyzed in the RMP and EIS. As part of this evaluation, the BLM also considers whether the existing ACEC designations should be modified or terminated. The Draft RMP and Draft EIS contains recommendations proposing potential ACECs for designation; public comment is requested. Public comments are reviewed and considered, and adjustments are made as necessary before the proposed RMP and Final EIS is released. Designation of ACECs is then incorporated in the Record of Decision (ROD) approving the RMP.
Regulations at 43 Code of Federal Regulations (CFR) part § 1610.7-2 state that during the resource management planning process, inventory data should be analyzed to determine whether there are areas within the Planning Area containing resources, values, systems or processes or hazards eligible for further consideration for designation as ACECs. In order to be eligible for designation as an ACEC, an area must meet at least one of both the relevance and importance criteria described below.
Relevance. An area meets the relevance criteria if it contains one or more of the following:
| 1. A significant historic, cultural, or scenic value (including but not limited to rare or sensitive archeological resources and religious or cultural resources important to Native Americans). |
| 2. A fish and wildlife resource (including but not limited to habitat for threatened, endangered, or sensitive species, or habitat essential for maintaining species diversity). |
| 3. A natural process or system (including but not limited to threatened, endangered, or sensitive plant species; rare, endemic, or relic plants or plant communities which are terrestrial, aquatic, or riparian; or rare geological features). |
| 4. Natural hazards (including but not limited to areas of avalanche, dangerous flooding, landslides, unstable soils, seismic activity, or dangerous cliffs). A hazard caused by human action may meet the relevance criteria if it is determined through the RMP process that it has become part of a natural process. |
Importance. The values, resources, system, processes, and/or hazards that allowed the area to meet the relevance criteria must have qualities that are in need of protection or special attention in order for the area to meet the importance criteria. The area meets the importance criteria if its relevance qualities can be characterized by one or more of the following:
| A. Has more than locally significant qualities which give it special worth, consequence, meaning, distinctiveness, or cause for concern, especially compared to any similar resource |
| B. Has qualities or circumstances that make it fragile, sensitive, rare, irreplaceable, exemplary, unique, endangered, threatened, or vulnerable to adverse change |
| C. Has been recognized as warranting protection in order to satisfy national priority concerns or to carry out the mandates of FLPMA |
| D. Has qualities that warrant highlighting in order to satisfy public or management concerns about safety and public welfare |
| E. Poses a substantial threat to human life and safety or to property |
Based on comments received during scoping and internal recommendations from BLM specialists, nine existing ACECs were nominated for continued designation and five expansion areas associated with these existing ACECs were proposed, as were 12 new ACEC nominations. These 26 nominated areas were evaluated using the relevance and importance criteria described above. Twenty-two of the nominations met both the relevance and importance criteria and are analyzed in the Draft RMP and Draft EIS.
Table F-2 lists the 26 nominations that were considered. This table lists the acreage of the proposed areas, the values of concern that warranted the nominations, the relevance and importance criteria that each area meets (numbers and letters correspond to the lists above), and whether the area was recommended for analysis in the Draft RMP and Draft EIS.
Additional information relevant to ACECs in the Planning Area, including the original completed ACEC Evaluation Forms and detailed maps of the existing or proposed ACECs, can be viewed in the Areas of Critical Environmental Concern Evaluation Report, which is available online at http://www.blm.gov/wy/st/en/programs/Planning/rmps/bighorn/docs.html.
Table F.2. Summary Results of the ACEC Evaluation Process
| Area | Acres | Value(s) of Concern | Relevance Criteria1 | Importance Criteria1 | Recommended | Comments |
|---|---|---|---|---|---|---|
| Existing ACECs (no expansion proposed) | ||||||
| Big Cedar Ridge | 264 | Paleontological | 1 | A, B | Yes | The area contains abundant paleontological resources, in particular, fossilized plants. Sites with such in situ preservation of entire plant communities are extremely rare, both regionally and nationally. |
| Red Gulch Dinosaur Tracksite | 1,798 | Paleontological | 1, 3 | A, B | Yes | The area contains the largest tracksite in Wyoming, and one of only a few worldwide from the Middle Jurassic Period. |
| Sheep Mountain Anticline | 11,528 | Geologic; Caves; Cultural; Scenic | 1, 3 | A, B | Yes | This area is composed of a classic Laramide anticline featured in textbooks nationwide and studied by geology classes from all over the world. The area also contains several caves, some of international significance, which provide recreational, educational, and research opportunities. |
| Spanish Point Karst | 6,627 | Caves; Recreational; Sinking Stream Segments; Water Quality | 1, 3 | A, B | Yes | The cave/karst system in the area is an important recharge area for the Madison aquifer. The area also contains recreational qualities due to good public access, scenic values, and varied potential recreation activities (primarily hiking, rock climbing, and caving). |
| Existing ACECs with Proposed Expansions | ||||||
| Brown/Howe | 5,516 | Paleontological | 1, 3 | A, B | Yes | This area contains paleontological values in the form of dinosaur fossils (primarily of Jurassic age), most notably from the suborder Theropoda and Sauropoda. |
| Brown/Howe | 15,247 | Paleontological | 1, 3 | A, B | Yes | The values of the expansion area are similar to the existing, but also includes vertebrate fossils and scientifically important paleobotanical, palynological (pollen), mammalian fossil, and dinosaur eggshell site resources. |
| Carter Mountain (existing) | 10,867 | Vegetation; Wildlife | 1, 2, 3 | B | Yes | This area contains alpine tundra and rare plants, and also includes for big game habitat (crucial winter range). |
| Carter Mountain | 5,706 | Cultural; Recreational; Special Status Species; Vegetation; Watershed; Wildlife; Soils | 1, 2, 3, 4 | A, B, C | Yes | The values of the expansion area are similar to the existing, but also include habitat for wildlife transition, parturition, and summer ranges. The area also includes special status species, and fragile and unstable soils and intense weather conditions that can cause hazards to visitors. |
| Five Springs Falls (existing) | 163 | Recreational; Scenic; Special Status Species | 1, 3 | A, B | Yes | Five Springs Falls area provides unique habitat for four plant species that are known to occur only in Wyoming and one other state. This unique habitat is composed of vertical cliff walls that are kept moist by spray from the waterfall. The Five Springs Falls Campground and waterfalls in the area are of recreational and scenic value. |
| Five Springs Falls | 1,646 | Geologic; Scenic; Public Safety | 1, 3, 4 | A, B | Yes | Geologic strata situated in the proposed ACEC expansion have been severely uplifted, folded, and faulted, resulting in an area of exceptional scenic and geologic interest and value; the steep topography is unstable, and downslope movements of soil and rock presents a public safety risk. |
| Little Mountain (existing) | 21,475 | Caves; Cultural; Paleontological; Scenic | 1, 3 | A, B, E | Yes | The karst topography has resulted in the capture and preservation of animal fossils, and the area contains sites from Prehistoric occupation. The mine shafts and tailings from uranium mining are a safety hazard. |
| Little Mountain expansion area | 47,635 | Wildlife; Special Status Species; Recreational; Vegetation; Scenic | 1, 2, 3 | A, B, C | Yes | This area contains big game seasonal and migration corridors, and known or potentially occurring BLM Sensitive Species and rare plant species habitat; these habitats are under threat from invasive species, human development, and livestock-wildlife disease transfer. The area includes numerous cultural sites (e.g., rock shelters, vision quest sites) and is an important area for hunting, fishing, wildlife viewing, and scenic geologic features. |
| Upper Owl Creek Area (existing) | 13,057 | Cultural; Fish; Recreational; Scenic; Soils; Special Status Species; Vegetation; Wildlife | 1, 2, 3 | A, B | Yes | The ACEC contains wildlife resources and special status species (including neotropical migrant birds, wolves, grizzly bears, moose, and wolverines), cultural resources, and primitive recreational opportunities (e.g., hiking, camping, fishing, and horseback riding). Vegetation communities include endemic plant species growing in “moonscapes” where rocky, sparsely-vegetated soils support low-growing, cushion plant communities, as well as forested areas that include old-growth tree stands. |
| Upper Owl Creek Area | 19,720 | Cultural; Fish; Recreational; Scenic; Soils; Special Status Species; Vegetation; Wildlife | 1, 2, 3 | A, B | Yes | The values of the expansion area are similar to the existing. |
| Proposed ACECs | ||||||
| Black-tailed Prairie Dog Complex | 182 | Wildlife; Special Status Species | 2, 3 | No | The area met the relevance criteria for fish and wildlife resources (black-tailed prairie dog, a species that has been petitioned for listing under the ESA) and natural process (potential habitat for black-footed ferret, an Endangered species). It did not meet the importance criteria because special management attention is not required to protect the black-tailed prairie dog complex; standard and routine management prescriptions afforded to special status wildlife species are sufficient. | |
| Chapman Bench | 23,326 | Special Status Species; Vegetation; Wildlife | 2, 3 | A, B, C | Yes | The area contains sagebrush habitat used by sensitive bird species and other wildlife. |
| Clarks Fork Basin/Polecat Bench West Paleontological Area | 23,895 | Paleontological; Scenic | 1, 3 | A, B | Yes | The area contains a stratigraphic contact zone and the paleontological and geochemical values associated with these rock layers that are exposed in only a few areas worldwide. |
| Clarks Fork Canyon | 12,259 | Geologic; Open Space; Recreational; Special Status Species; Wildlife | 2, 3 | A, B | Yes | The area contains geologic, crucial winter range for big game, one of only two ranges for mountain goats in the state and one of the largest bighorn sheep ranges in the country, special status species habitat (including plant, sagebrush obligate wildlife, and Yellowstone cutthroat trout), open space, and recreational resources and uses including along the Clarks Fork of the Yellowstone River. |
| Fifteen Mile and Manderson White-tailed Prairie Dog Complex | 7,917 | Wildlife; Special Status Species | 2 | No | The area met the relevance criteria for fish and wildlife resources (BLM Sensitive white-tailed prairie dog). It did not meet the importance criteria special management attention is not required to protect the white-tailed prairie dog complex; standard and routine management prescriptions afforded to special status wildlife species are sufficient. | |
| Foster Gulch Paleontological Area | 27,302 | Paleontological; Scenic | 1, 3 | A, B | Yes | The area contains a stratigraphic contact zone and the paleontological and geochemical values associated with these rock layers that are exposed in only a few areas worldwide. |
| McCullough Peaks South Paleontological Area | 6,994 | Paleontological; Scenic | 1, 3 | A, B | Yes | The area contains a stratigraphic contact zone and the paleontological and geochemical values associated with these rock layers that are exposed in only a few areas worldwide. |
| McCullough Peaks/YU Bench | 298,402 | Scenic; Historic; Cultural; Wildlife; Recreational; Geologic | 1, 2, 3, 4 | No | The area met the relevance criteria for significant historic, cultural, or scenic value; fish and wildlife resources; natural process or system (for sage-grouse and wild horse habitat and geology); and natural hazards. It did not meet the importance criteria as management concerns are similar to other locations and can be addressed through other means (e.g., Herd Management Areas). | |
| Rainbow Canyon | 1,443 | Paleontological; Geologic; Scenic | 1, 3 | A, B | Yes | The area contains scenic and geologic resources, as well as paleontological resources that include dinosaurian and paleobotanical fossils. |
| Rattlesnake Mountain | 19,119 | Special Status Species; Vegetation; Wildlife | 2, 3 | A, B, C | Yes | The area contains wildlife habitat (big game seasonal habitat and migration corridors), vegetation communities associated with the volcanic and limestone soils, and special status wildlife and plant species habitat. |
| Sheep Mountain | 25,153 | Vegetation; Wildlife; Special Status Species | 1, 2, 3 | A, B, C | Yes | The area contains wildlife habitat (big game seasonal habitat and migration corridors) and vegetation communities associated with the volcanic and limestone soils. |
| Shoshone River Parcels | 424 | Wildlife | 1, 2, 3, 4 | No | The area contains riparian and river related values. Met the relevance criteria for significant historic, cultural, or scenic value; fish and wildlife resources; natural process or system; and natural hazards. It did not meet the importance criteria as management and other concerns are similar to other riparian areas in the Planning Area. | |
| 1 Values in these columns correspond to the numbers or letters in the lists provided previously in this appendix. ACEC Area of Critical Environmental Concern BLM Bureau of Land Management ESA Endangered Species Act-Not applicable | ||||||