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<br />rate of lateral migration. The most significant change is the lowering of <br />the base level. This has resulted in channel rejuvenation (over-steepening <br />of the grade headword, thus increasing the gradient) for the South Fork as <br />well as the mainstem San Miguel Rivers. This has caused the original <br />channel to abandon its foodplain and become entrenched. As a result, <br />subsequent future flows are more damaging, accelerating bank erosion as the <br />stream attempts to gain enough width to re-establish a floodplain and <br />meander geometry for natural energy dissipation. <br />Associated riparian vegetation has been similarly impacted. Former <br />wetlands and riparian vegetation have been lost to gravel mining and mass <br />wasting and erosion within the floodplain. The water table has dropped <br />with the lowering of the base flows which has killed narrow-leaf cottonwood <br />in areas such as the Mary E campground. Remnant riparian vegetation still <br />exists in places which have not yet eroded away or succumb to the lack of <br />ground water. Included are mixtures of narrow-leaf cottonwood with blue <br />spruce and engleman spruce riparian habitat. Remnant willow communities <br />are located on present terraces, formerly within the floodplain. <br />I have reviewed the general species list of potential federally listed and <br />candidate species occurring within the San Juan Mountains geographic area <br />of the GMUG National Forest (USFWS March 24, 1995) to identify potential <br />species or habitat of concern. Based upon the habitats effected and known <br />occurrence of species andlor habitat, federally listed, proposed, or <br />candidate species of concern include the bald eagle, Mexican spotted owl, <br />and southwestern willow flycatcher. <br />I have also reviewed the current Forest Service sensitive species list for <br />the GMUG National Forest (USFS March 23, 1994) and identified potential <br />species end habitat of concern. Included ere the northern leopard frog, <br />tiger salamander, and American bittern. <br />Effects of the Proposed Action <br />Each species will be analyzed separately for the effects of the proposed <br />action. <br />Bald eagle - Haliaeetus laucoceohalus <br />endangered species <br />The bald eagle is distributed throughout a majority of North America and <br />nests throughout the Rocky Mountain region in wooded mountains and river <br />areas of Montana, Wyoming, Colorado, and North Dakota. The bald eagle's <br />breeding range has diminished, and it had disappeared from many parts of <br />its historical range during the latter half of this century. Recently, <br />eagles have been successful in reestablishing historical breeding sites and <br />new territories. <br />Bald eagles generally nest in areas which provide adequate food and are in <br />close proximity to open water. Eagles will often return to the same nest <br />in subsequent years repairing the nest or rebuilding it if necessary. <br />During the nesting season their diet primarily consists of fish, with other <br />food sources including songbirds, invertebrates, and other small animals. <br />Bald eagles remain within their nesting territory throughout the summer <br />months. Migration from breeding areas generally takes place between <br />September and December. Eagles will winter as far north as there is <br />available food and water. Winter habitat includes large major river <br />13 <br />