WSP08184

• File Number: 8200.765
• Description: White River General
• State: CO
• Basin: Yampa/White
• Water Division: 6
• Date: 11/1/1966
• Author: USFS
• Title: Water and Related Land Resources - White River Basin in Colorado
• Water Supply Pro - Doc Type: Report/Study

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Most of the unit is at elevations between 7,000 and 8,000 feet but
there are extremes from 6,400 to 8,800 feet. Soil moisture conditions
are more favorable for plant growth due to higher precipitation and
lower evaporation associated with higher elevations. Data from the
Marvine station show a mean annual precipitation of about 20 inches,
a mean annual temperature of nearly 40. F., and a frost-free period
of 47 days. Since unit 5 extends west to the State line, a range
of from 15 to 20 inches in annual precipitation and 45 to 100 days
in length of frost-free period can be expected.

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Parent materials consist of mixed alluvium, colluvium, and outwash
deposits along streams and valleys. Gravelly and stony valley fill
is extensive along the lower mountain slopes. Parent rocks are chiefly
sandstones, quartzites, shales and basalt. They have furnished the
source for much reworked material in which soils have formed.

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The approximate composition of the unit by Great Soil Groups is shown
below. Estimates were not made for Regoso1s as they are included
within the zonal soils:

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Percent 1949 Great Soil Group 1965 Great Group. Subgroup
or Family
45 Chernozem soils Argiudolls and Argiborolls
Hap1udolls and Hap10boro11s
35 Chestnut soils Argiusto11s and Hap1usto11s
15 Lithoso1s Hap1ustolls and Hap1udolls
(Lithic)
3 Alluvial soils Hap1ustolls and Hap1a,!uolls
2 Land types Land types
(Rock outcrop) (Rock outcrop)

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Dominant soils of this unit have dark gray or dark grayish brown
surface layers that are high in organic matter content. Surface
layers are loamy with loam and sandy loam textures being most common.
On steep colluvial slopes coarse fragments from higher lying rock
ledges and outcrops are usually scattered over the surface soil.
Subsoils are more clayey and may be sandy clay loam to clay in tex-
ture. Many subsoils contain gravel, stone, and rock fragments. Lime
is usually leached to depths of 40 to 60 inches.

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Moderately deep and deep soils are intermingled within this unit.
At depths between 20 and 40 inches there is usually sandstone, shale
or basalt under moderately deep soils. Deep soils have formed in
valley fill and may have dark colored buried soils within the upper

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