27—Lapine paragravelly ashy loamy coarse sand, 35 to 55 percent south slopes
Map Unit Setting
General location: Mountainsides in the southeastern corner of the park
Major land resource area (MLRA): 6
Elevation: 4,500 to 6,500 feet
Average annual precipitation: 30 to 50 inches
Average annual air temperature: 38 to 42 degrees F
Frost-free period: 10 to 50 days
Map Unit Composition
Lapine and similar soils: 90 percent
Minor components: 10 percent
Characteristics of the Lapine and Similar Soils
Setting
Landform: Ashflow
Geomorphic position: Pumice and ashfall and ashflow material on mountainsides
Parent material: Ash and pumice
Properties and qualities
Slope: 35 to 55 percent; northeast to northwest aspects
Percentage of surface covered with stones and boulders: None
Restrictive features: None within a depth of 60 inches
Drainage class: Excessively drained
Permeability: Very rapid
Flooding: Not present
Water table: Not present
Ponding: Not present
Available water capacity: About 6.2 inches
Interpretive groups
Ecological site: Forestland—(006XY700OR) Pinus ponderosa-Abies/Symphoricarpos hesperius
Typical profile
Oi—0 to 2 inches; slightly decomposed plant material
A—2 to 8 inches; paragravelly ashy loamy coarse sand
Bw1—8 to 15 inches; paragravelly ashy loamy sand
Bw2—15 to 24 inches; very paragravelly ashy sand
C—24 to 60 inches; extremely paragravelly ashy sand
Characteristics of the Minor Components
Similar soils that have buried soil material at a depth of 25 to 40 inches
Percentage of map unit: 9 percent
Landform: Ashfall
Geomorphic position: Mountainsides
Rock outcrop
Percentage of map unit: 1 percent
Landform: Mountain
Geomorphic position: Lava flows on mountainsides
Major Soil Features and Properties Affecting Management
Lapine soil
• Low soil strength
• Steepness of slope
• High pumice content
• Water erosion
• Very rapid permeability
