GENERAL30783

• Permit No: C1981010
• IBM Index Class Name: General Documents
• Doc Date: 4/8/1988
• Doc Name: Proposed Decision & Findings of Compliance for PR2 & RN1
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

regions of Northwestern Colorado. They represent soils that grade from
recently developed soil bodies with minimum horizon development (F.ntisols) to
older soils with well-defined diagnostic horizons (Mollisols).
Overall, the soils found in the proposed permit area are relatively deep and
fairly well-drained. Effective rooting depth varies from two to sixty inches
within the area. The deepest soils yielding the greatest rooting depths occur
within valleys and on the leeward side of ridges. Soil reaction is slightly
acid to moderately alkaline over the permit area with the exception of
inclusions of small scattered areas with saline substrata. These small areas
have probably formed in place from weathered sodic shales.
Vegetation in the area grows largely in response to macro climatic influences
of the region. The north-facing slopes, having moderate to deep soils, a
relatively me sic moisture regime, and favorahle levels of insolation
throughout the year are characterized by well-developed mountain shrub
communities. On the colluvial toe-slopes, communities dominated by sagebrush
and some grasses occur. On the south-facing slopes behind the ridgeline of
the Williams Fork mountains, vegetative communities are not as well-developed
in terms of cover, density and production due to the less favorable soils,
moisture regime, and increased solar insolation. The trend in these areas is
toward communities dominated by juniper, pinyon, mountain mahogany and
xerophytes.
Within the permit area, natural vegetative communities have heen modified to
varying degrees by man and domestic animals. Much of the land along
toe-slopes and valley bottoms has been cleared of native vegetation and is
currently utilized for dryland agriculture. Most of the north-facing slopes
in the area have been historically used for the grazing of sheep and/or
cattle. Due to the above, the permit area is characterized by a mosaic
distribution of communities.
In transversing the permit area from east to west, the mountain shrub
community begins to thin (in terms of density and cover) until it is replaced
on the far west by a community of big sagebrush and grasses. Oescendina from
the ridge of the Williams Fork Mountains (proceeding northward), several
changes in community composition are noted. At elevations above 7,200 feet,
the mountain shrub community is characterized by Gambel's oak, which is
dominant over serviceberry and chokecherry, Snowberry is the most conspicuous
understory component, with an occasional big sagebrush, rubber rabbitbrush, or
bitterbrvsh. With a decrease in elevation comes a corresponding decrease in
oak dominance. Sagebrush, serviceberry and chokecherry are interspersed,
while oak dominates only in east-facing slopes. Entering the lowest
elevations, the serviceberry/chokecherry component diminishes, leaving a
community dominated by sagebrush, rabbithrush, and grasses.
Due to the presence of many and varied habitat types, many types of fauna are
found in and adjacent to the permit area. Antelope are found year round in
the lower sagebrush and cropland areas. Mule deer are found in the mountain
shrub community, sagebrush/grass community and pinyon/juniper community (to
the south of the permit area) during all seasons of the year. Elk use the
permit area primarily in the fall, winter, and early spring. In the summer
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