Crater Lake Institute
 

 Home | Site Map | About Us | Donate/Join Us | Contact Us | CLI Store | Press Room

 
 
 You are here: Home > Online Library > Soil Survey of Crater Lake NP > Grousehill-Llaorock complex
   
Soil Survey of Crater Lake National Park, Oregon

 

Detailed Soil Map Units

 

<< Previous | Table of Contents | Next >>

 

23—Grousehill-Llaorock complex, 5 to 35 percent slopes Map Unit Setting

 

General location: Glaciated side slopes of mountains and ridges

Major land resource area (MLRA): 3

Elevation: 4,500 to 6,000 feet

Average annual precipitation: 50 to 70 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 moraine on ridges and mountainsides

Parent material: Ash over glacial till

 

Properties and qualities

 

Slope: 5 to 35 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—(003XY701OR) Tsuga mertensiana/Vaccinium scoparium/Chimaphila umbellata

 

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: Lava flow

Geomorphic position: Side slopes of glaciated valleys

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

 

Properties and qualities

 

Slope: 5 to 35 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—(003XY701OR) Tsuga mertensiana/Vaccinium scoparium/Chimaphila umbellata

 

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: Stratovolcano

Geomorphic position: Ashfall deposits on mountainsides

 

Rock outcrop

 

Percentage of map unit: 5 percent

Landform: Lava flow

Geomorphic position: Andesitic lava flows on side slopes of ridges and mountains

 

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

 

 

 

 

 

 Site Navigation

  Advocacy

  Arts

  Education

  Crater Lake News

  Cultural History

  Natural History

  Online Library

     Articles

     Books

        Browse all by Author

        Browse all by Title

        Cultural History

           General

           Historic Structures

           Native American

           Oral Histories

        Natural History

           Flora and Fauna

           General

        Park Management

           General

           Planning

        Research

           Atmosphere

           Fauna

           Fire

           Flora

           General

           Geology

           Limnology

           Visitation

     Nature Notes

     Images

     Maps

  Planning a Visit

  Research