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Fisheries Habitat Beaver can have a dramatic effect on fisheries habitat, depending on the natural channel size, characteristics, and endemic fish species present. In flatter gradient streams of the midwestern United States, beaver ponding covers streambed gravels, reducing habitat diversity and salmonid spawning habitat (Churchill, 1980). In contrast, in small moun- tain streams of the West, beaver ponds provide up to 400 percent increases in rearing space, which is often far more limiting than spawning habitat (Gard, 1961). In streams larger than fourth order, beaver have little influence on channel characteristics, because the constructed dams are rela- tively temporary, and other hydraulic forces more severely influence chan- nel characteristics. In some cases, spawning migration blocks can occur from beaver dams, particularly with those species that are dependent on migrations during low streamflow migrations. In western Montana, bull trout, brown trout, or kokanee salmon can be adversely affected. Migra- tions occurring during higher runoff conditions such as cutthroat trout are influenced to a lesser degree. Reductions in spawning success may be offset by increases in rearing space provided by beaver ponds (Gard, 1961). Esthetics and Recreation Water is often considered to enhance the esthetic quality of a scenic area. The presence of small streams is often noticed only when a stream is in the foreground of a viewer; however, the larger expanse of water created by beaver ponds is noticeable from a greater distance, as is the vegetative diversity that is often associated with the beaver pond. The variety that a beaver pond can create in an otherwise stream-oriented en- vironment offers visual diversity. The disproportionate numbers and diversity of wildlife associated with beaver ponds oft~n attract recreationists, in part, because wildlife is often more viewable in the semi-open setting of some beaver ponds. Beaver and sign of their activity is one of the more viewable forms of wildlife that can add measurably to a recreation experience. Beaver ponds can create fishing recreational opportunities, because the larger open bodies of water are easier to fish than adjacent streams. Parents with children find these ponds good opportunities to fish because the ponds are rela- tively safer for young children than a flowing stream. Range Management In certain situations, beaver have influenced the vegetative state of riparian and adjacent lands through the construction of ponds and the cut- ting of deciduous overstory as food supplies. Vegetation adjacent to ponds is often composed of .types more mesic than those without ponds, due to the higher water tables and moister soils associated with ponding. This bea- ver activity can influence the distribution of livestock and the response of vegetation to livestock use. Ponds can create partial or complete livestock barriers to individual plants adjacent to water bodies. Some plant species, such as deciduous shrubs, are vulnerable to severe damage 75