Alternative A prohibits surface-disturbing activities such as geophysical exploration (except casual use) and construction activities (except those related to development of recreation or interpretive areas dealing with rare plants). Prohibiting surface-disturbing activities would result in adverse impacts by limiting these activities. This restriction would benefit special status plant species and scenic and recreational values of concern in the ACEC.
Withdrawing the ACEC from appropriations under the mining laws would result in minimal adverse impacts to locatable minerals because the potential for gypsum and bentonite is low in the ACEC. The Five Springs Falls ACEC is open to exploration and development of salable minerals and leasable minerals are open with an NSO restriction. However, there is no identified development potential for oil and gas and there is low potential for sand and gravel within this ACEC. Therefore, impacts would be minimal for these minerals.
Under Alternative A, managing the Five Springs Falls ACEC as an ROW avoidance/mitigation area would result in adverse impacts to this resource use by limiting new ROW authorizations in the ACEC. ROW management would reduce or mitigate surface disturbance and would help protect scenic and recreational values of concern. Requiring intensive mitigation for new ROWs would further benefit these values by reducing the impacts of new ROWs.
Limiting motorized travel in the ACEC to designated roads and trails would result in adverse impacts to motorized vehicle use. This travel restriction would reduce the available routes and would allow the closure of routes that result in adverse impacts to the values of concern.
Under Alternative A, restricting the use of heavy equipment in the Five Springs Falls ACEC may result in adverse impacts to fire and fuels management by limiting the ability to effectively and efficiently control wildland fires in the ACEC. Restricting these surface-disturbing activities would result in beneficial impacts by limiting potential degradation or destruction of the values of concern. However, limiting available options to control the spread or severity of wildfire may result in more catastrophic wildfires.
Alternative B would expand the Five Springs Falls ACEC by 1,646 acres. Management and impacts described for Alternative A, with the exception of minerals, would apply to the expanded area unless otherwise noted. The larger size of the expanded ACEC, and the expansion of common management to include this area, would result in similar types of impacts to Alternative A, but to a greater extent.
Under Alternative B, restrictions on mineral development would result in adverse impacts to the use of these resources. Withdrawing the expansion area from appropriation under the mining laws would result in greater adverse impacts than Alternative A, particularly on the 1,646 acres of high-potential for bentonite. Valid existing mining claims represent valid existing rights and would not be affected by the withdrawal, although no new claims could be staked. This withdrawal would benefit the values of concern by reducing the impacts of surface disturbance. The degree of impacts from this withdrawal would be greater than under Alternative A, under which not withdrawing the area and allowing the staking of mining claims may result in adverse impacts to special status plant species habitat and scenic quality due to disturbance associated with mineral development. Making the ACEC administratively unavailable for mineral leasing and closing it to mineral materials disposal would result in minimal adverse impacts because the development potential for oil and gas ranges from low to none and the potential for sand and gravel is low. Both the adverse and beneficial impacts of these actions would be greater than for the existing area and the expansion area than under Alternative A, under which the BLM manages the area as open to mineral leasing and mineral materials disposal.
Managing the existing and expansion area of the Five Springs Falls ACEC as an ROW avoidance/mitigation area would result in greater adverse and beneficial impacts than under Alternative A, under which the expansion area is primarily open to ROW authorizations.
As under Alternative A, Alternative B limits motorized vehicle use in the existing and expansion area of the Five Springs Falls ACEC to designated roads and trails.
Under Alternative C, the BLM would not designate the area as an ACEC, and would manage it in accordance with multiple use principles consistent with other resource objectives.
Alternative C includes the least restrictions on mineral development because the area is available for locatable mineral entry, open to mineral leasing, and open for mineral materials disposal. Impacts to values of concern in the Five Springs Falls area from the development of minerals would be similar to those under Alternative A.
Management under this alternative would be the least restrictive for ROW authorizations because the area is primarily open to ROW authorizations and other surface-disturbing activities. Standard guidelines related to surface-disturbing activities would apply, but there would be more surface disturbance in the area compared to alternatives A and B, increasing the potential for damage to values of concern.
Under Alternative C, the BLM would limit motorized vehicle use to designated roads and trails (1,646 acres) or close some area to motorized travel (163 acres). Impacts from travel management would be the same as under the other alternatives.
Under Alternative D, management of and impacts from the Five Springs Falls ACEC would be the same as under Alternative A, with the exceptions identified below.
As under Alternative B, under Alternative D the BLM would close the existing Five Springs Falls ACEC to mineral materials disposal and make it administratively unavailable for mineral leasing under Alternative D. Therefore, impacts under Alternative D would be the same as under Alternative B in this area. Similar to Alternative C, the area proposed for expansion under Alternative B would be available for locatable mineral entry, primarily open to oil and gas leasing with moderate constraints (1,526 acres), and open to mineral materials disposal. Under Alternative D, impacts from the management of mineral exploration and development in the Alternative B expansion area would be similar to Alternative C.
As under Alternative B, under Alternative D the BLM would manage the existing Five Springs Falls ACEC and the expansion area proposed under Alternative B as an ROW avoidance/mitigation area. However, unlike Alternative B, intensive mitigation is not required for additional ROW authorizations. The additional adverse impacts to ROWs and additional benefits to special status plants species and scenic and recreational features from this additional mitigation would not occur under this alternative.
As under Alternative A, the existing area of the Five Springs Falls ACEC and the expansion area proposed under Alternative B are limited to designated roads and trails under Alternative D; impacts from this management would be the same as described under Alternative A.
Under Alternative A, the BLM designates the Little Mountain area as an ACEC (21,475 acres) and designates and expands the area by 47,635 acres under Alternative B. The BLM would not designate these areas as ACECs under Alternative C. Under Alternative D, the BLM would designate the ACEC with the Alternative A boundaries, and would manage the area proposed for expansion under Alternative B as the Craig Thomas Little Mountain SMA. Although the Craig Thomas Little Mountain SMA exists and would continue under all the alternatives, the BLM does not apply special management in the area and proposes special management only under Alternative D. Management of this area would vary by alternative. Values of concern for this area includes caves, cultural and paleontological resources, and scenic qualities. In addition, the proposed expansion area contains wildlife and vegetation resources, including big game and special status species habitat and important plant populations. Threats to the ACEC and SMA include surface disturbance from mineral (including gravel pits, uranium, and limestone) and ROW development, timber extraction, recreational and OHV use, and invasive species, which affect habitat for special status species and have the potential to disturb wintering wildlife.