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Vantage to Pomona Heights Chapter 4 230 kV Transmission Line Project FEIS Environmental Consequences PAGE 4-94 designated concentration area, no identifiable impacts are anticipated to occur to mule deer through construction, operation, and maintenance of the proposed Project. Route Segment 2d passes through the Rattlesnake Elk Winter Range Regular Concentration Area for 6.2 miles of the seven-mile route segment. RDFs to minimize impacts to elk will include a seasonal restriction on construction. Specifically, construction would be avoided during the wintering season, typically December 1 through March 1, or as defined by WDFW for each big game population in question (Section 2.3). The avoidance RDF is anticipated to be effective at minimizing impacts to elk; therefore, impacts are expected to be low for the 6.2 miles of the route segment that are within designated winter range. As Route Segment 2d descends the slopes near the Columbia River, it passes near and over steep bluffs and bands of cliffs, which provide nesting substrates for raptors. Several nests of prairie falcons have been documented within one mile of the route segment—the closest of which is approximately 0.4 mile away. Prairie falcon is not a special status species, but it is sensitive to nest disturbance and indicates suitable nesting cliffs that could provide nesting substrates for other raptor species. Further south, on the south- facing slopes between Cold Creek and the Columbia River, a ferruginous hawk nesting territory with three documented nests was recorded in 2010. Two of the three nests are within a half mile of the route segment with the nearest located approximately 0.25 from the route segment. Potential impacts to raptors would occur from biological disturbance during construction activities or from injury or mortality from vehicle strikes or interactions with other equipment used during construction. Noise from construction equipment and general construction activities could disturb and displace individuals during the sensitive nesting period. RDFs to minimize impact on raptors are described in Sections 4.3.3.1 and 4.3.3.2. RDFs include the stipulation that, within the breeding season, construction would be avoided within species- specific raptor nest buffers to avoid disturbing nesting birds (0.5 mile for ferruginous hawk and 0.25 mile for prairie falcon; see RDFs in Chapter 2). Following implementation of RDFs, impact levels on prairie falcons are expected to be moderate for 2.8 miles. All habitat disturbance associated with Route Segment 2d would be located within the Regularly Occupied Habitat MU for Sage-Grouse. Construction activities would disturb less than one percent of Regularly Occupied Habitat (Table 4.3-7). Anticipated ground disturbance includes 34.1 acres of suitable Sage-Grouse habitat and 7.8 acres of marginal habitat (Table 4.3-8). With the implementation of RDFs (Sections 4.3.3.1 and 4.3.3.2), the scale of disturbance and degradation to Sage-Grouse habitat is anticipated to be low for 1.3 miles and moderate for 5.7 miles. The Range 12 Fire of 2016 burned approximately 4.5 miles along Route Segment 2d. As previously stated, post-fire restoration efforts for the Range 12 fire are in development and impacts to wildlife habitat have not been fully assessed following the fire. Construction of Route Segment 2d would require an estimated 50 new structures, all of which would be located greater than 0.25 mile of an existing transmission line (Table 4.3-5). Fourteen percent of the Route Segment 2d ROW is within the estimated Sage-Grouse population range, but none of the route segment’s ROW is within the core population range (Figure 3.3-4). No active or inactive leks are known to occur within four miles of Route Segment 2d (Table 4.3-6). Impacts to lekking Sage-Grouse associated with the construction of Route Segment 2d are anticipated to be low for the entire 7.0-mile length of the route segment. 4.3.4.8 Route Segment 3a The entirety of anticipated ground disturbance for this short route segment is anticipated to occur in sagebrush/perennial grassland (1.2 acres) and, thus, is considered a long-term impact. RDFs would be