LOCATION FRISCO                  CO+WY

Established Series
Rev. RLM/CRP/JCK
04/2018

FRISCO SERIES

The Frisco series consists of very deep, well drained soils formed in colluvium, till, slope alluvium or slide deposits. These soils are on mountain slopes, moraines, dip slopes and landslides. Slopes are 2 to 75 percent. Mean annual precipitation is about 762 mm, and mean annual air temperature is about 1.1 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Eutric Haplocryalfs

TYPICAL PEDON: Frisco sandy loam - forested, on a 25 to 65 percent slope. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 2.5 cm; undecomposed needles, bark, and twigs.

Oe--2.5 to 8 cm; partially decomposed organic materials, principally needles, bark and twigs.

E--8 to 48 cm; very pale brown (10YR 7/3) sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, very friable; 10 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (30 to 61 cm thick)

Bt1--48 to 130 cm; light yellowish brown (10YR 6/4) very stony sandy clay loam, yellowish brown (10YR 5/6) moist; less than 5 percent very pale brown (10YR 7/3) uncoated sand grains on peds; moderate medium subangular blocky structure; slightly hard, very friable; faint patchy clay films on ped faces and on surfaces along root channels; 60 percent stones; slightly acid (pH 6.5); gradual wavy boundary. (10 to 81 cm thick)

Bt2--130 to 160 cm; light yellowish brown (10YR 6/4) very stony sandy clay loam, yellowish brown (10YR 5/6) moist; strong and moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; faint nearly continuous clay films on ped faces and on surfaces along root channels and pores; 60 percent stones; slightly acid (pH 6.4); gradual smooth boundary. (20 to 76 cm thick)

Bt3--160 to 178 cm; light yellowish brown (10YR 6/4) very stony sandy clay loam, yellowish brown (10YR 5/6) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; faint patchy clay films on ped faces; 60 percent stones; slightly acid (pH 6.4); gradual smooth boundary. (10 to 25 cm thick)

C--178 to 211 cm; very pale brown (10YR 7/4) very stony sandy clay loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, friable; 60 percent stones; slightly acid (pH 6.4).

TYPE LOCATION: Summit County, Colorado; about 8 kilometers northeast of Breckenridge; NE1/4 of Sec. 29, T. 6 S., R. 77 W. Frisco USGS quad; approximate latitude 39 degrees 30 minutes 18 seconds N. and approximate longitude 106 degrees 00 minutes 42 seconds W., NAD 27.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 0.0 to 4.4 degrees C
Particle-size control section (weighted average):
Clay content - 18 to 35 percent
Rock fragments - 35 to 80 percent, dominantly greater than 250 mm

Note: Some pedons have a thin A horizon above or in place of an E.

E horizon
Hue: 7.5YR, 10YR, 2.5Y or 5Y
Value: 5, 6, 7 or 8 dry; 4, 5, 6 or 7 moist
Chroma: 1, 2, 3 or 4
Texture: sandy loam or loam
Clay content: 10 to 22 percent
Rock fragments: 10 to 80 percent
Reaction: pH 5.6 to 7.0

Bt horizons
Hue: 7.5YR, 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 1, 2, 3, 4 or 6
Texture: sandy clay loam or loam
Clay content: 18 to 35 percent
Rock fragments: 35 to 80 percent, dominantly stones
Reaction: pH 5.6 to 7.0

C horizons
Hue: 7.5YR, 10YR, 2.5Y or 5Y
Value: 5, 6 or 7 dry; 4, 5 or 6 moist
Chroma: 1, 2, 3, 4 or 6
Texture: sandy loam or sandy clay loam
Clay content: 12 to 30 percent
Rock fragments: 35 to 85 percent, dominantly stones
Reaction: pH 5.6 to 7.0

COMPETING SERIES:
Helmville (MT) - have an accumulation of secondary calcium carbonate
Highwood (MT) - do not have rock fragments more than 250 mm in size
Lonniebee (MT) - are moderately deep to a lithic contact
Needleton (CO) - have hue redder than 7.5YR
Tamarron (CO) - are moderately deep to a paralithic contact
Tigeron (MT) - have an albic horizon; have argillic horizons consisting of lamellae
Watsondraw (WY) - have less than 35 percent rock fragments below the argillic horizon
Worock (MT) - have rock fragments that are dominantly less than 250 mm in size

GEOGRAPHIC SETTING:
Landform - mountain slopes, moraines, dip slopes and landslides
Elevation: 2,438 to 3,505 meters
Slope - 2 to 75 percent
Parent material - colluvium, till, slope alluvium or slide deposits
Mean annual precipitation - 610 to 1,143 mm
Mean annual air temperature - -1.1 to 3.3 degrees C
Frost free period - 30 to 70 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Peeler and Grenadier soils.

DRAINAGE AND PERMEABILITY: Well drained; moderate to moderately slow permeability.

USE AND VEGETATION: Frisco soils are used for wildlife habitat, recreation and timber production. Native vegetation is mainly subalpine fir, Engelmann spruce, whortleberry, Oregon boxleaf and creeping or common juniper.

DISTRIBUTION AND EXTENT: Frisco soils are extensive in mountainous areas of Colorado and Wyoming. MLRA 43B and 48A.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Summit County Area, Colorado, 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from 8 to 48 cm (E horizon)
Argillic horizon - from 48 to 175 cm (Bt1, Bt2 and Bt3 horizons)
Particle-size control section - from 48 to 98 cm (part of the Bt1 horizon)

Frisco soils have a cryic temperature regime and a udic moisture regime.

---

National Cooperative Soil Survey
U.S.A.