37 24—Grousehill-Llaorock complex, dry, 0 to 30 percent slopes

24—Grousehill-Llaorock complex, dry, 0 to 30 percent slopes

 Map Unit Setting

 General location: Side slopes of mountains and ridges in the southeastern part of the park

Major land resource area (MLRA): 3

Elevation: 5,500 to 6,000 feet

Average annual precipitation: 45 to 60 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 10 to 50 days

 Map Unit Composition

 Grousehill and similar soils: 65 percent

Llaorock and similar soils: 20 percent

Minor components: 15 percent

 Characteristics of the Grousehill and Similar Soils

 Setting

 Landform: Ground moraine

Geomorphic position: Glacial moraines on ridges and mountainsides

Parent material: Ash over glacial till

 Properties and qualities

 Slope: 0 to 30 percent

Percentage of surface covered with stones and boulders: 3 percent

Restrictive feature: Duripan at a depth of 20 to 40 inches

Drainage class: Moderately well drained

Permeability: Moderate

Flooding: Not present

Water table: Present (see table 20)

Ponding: Not present

Available water capacity: About 12.8 inches

 Interpretive groups

 Ecological site: Forestland—(003XY703OR) Abies/Carex inops

 Typical profile

 Oi—0 to 3 inches; slightly decomposed plant material

A—3 to 10 inches; gravelly medial loam

Bw1—10 to 31 inches; very cobbly medial loam

Bw2—31 to 39 inches; very cobbly medial loam

Bqm—39 to 56 inches; moderately cemented duripan

 Characteristics of the Llaorock and Similar Soils

 Setting

 Landform: Stratovolcano

Geomorphic position: Side slopes of glaciated valleys

Parent material: Ash mixed with residuum and colluvium derived from andesite

 Properties and qualities

 Slope: 0 to 30 percent

Percentage of surface covered with stones and boulders: 3 percent

Restrictive features: None within a depth of 60 inches

Drainage class: Somewhat excessively drained

Permeability: Rapid

Flooding: Not present

Water table: Not present

Ponding: Not present

Available water capacity: About 9 inches

 Interpretive groups

 Ecological site: Forestland—(003XY704OR) Abies/Carex inops

 Typical profile

 Oi—0 to 1 inch; slightly decomposed plant material

A—1 inch to 7 inches; gravelly ashy sandy loam

AB—7 to 14 inches; very stony ashy sandy loam

Bw1—14 to 24 inches; extremely stony medial sandy loam

Bw2—24 to 61 inches; extremely stony medial sandy loam

 Characteristics of the Minor Components

 Castlecrest soils

 Percentage of map unit: 10 percent

Landform: Ashfall

Geomorphic position: Ashfall deposits on mountainsides

 Rock outcrop

 Percentage of map unit: 5 percent

Landform: Stratovolcano

Geomorphic position: Side slopes of glaciated valleys

 Major Soil Features and Properties Affecting Management

 Grousehill soil

 • Rock fragments on surface

• Rock fragments in soil profile

• Depth to hardpan

• Wetness

 Llaorock soil

 • Rock fragments on surface

• Rock fragments in soil profile

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