LOCATION STAGPOINT CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, frigid Andic Haplohumults
TYPICAL PEDON: Stagpoint loam, on a west facing 12 percent slope under a cover of white fir, red fir and shrubs at an elevation of 5325 feet, (1623 m). When described on 7/29/97 the soil was dry throughout. (Colors are for dry soil unless otherwise noted)
Oi--0 to 0.5 inches, (0 to 1 cm); needles and twigs. (0.5 to 3 inches, (1.27 to 8 cm) thick)
A--0.5 to 4 inches, (1 to 10 cm); brown (7.5YR 5/4) loam, dark brown (7.5YR 3/3) moist; 16 percent clay; weak fine subangular blocky structure parting to single grain; loose, very friable, nonsticky and nonplastic; common very fine roots; many very fine irregular pores; 10 percent gravel; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 10.8; abrupt smooth boundary. (2 to 7 inches, (5 to 18 cm) thick)
Bt1--4 to 10 inches, (10 to 25 cm); light brown (7.5YR 6/4) gravelly loam, dark brown (7.5YR 3/3) moist; 14 percent clay; weak medium subangular blocky structure parting to single grain; slightly hard, very friable, nonsticky and slightly plastic; common very fine to medium roots; common very fine tubular pores; few faint discontinuous clay films between sand grains; 18 percent gravel; moderately acid, pH 5.7 by Hellige-Truog; NaF pH 10.9; abrupt smooth boundary. (2 to 10 inches, (5 to 25 cm) thick)
Bt2--10 to 17 inches, (25 to 43 cm); pink (7.5YR 7/4) very gravelly loam, brown (7.5YR 4/4) moist; 20 percent clay; weak medium subangular blocky structure parting to single grain; slightly hard, friable, slightly sticky and slightly plastic; common very fine to medium and few coarse roots; few very fine tubular pores; few faint discontinuous clay films between sand grains; 30 percent gravel and 15 percent cobbles; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 10.3; clear smooth boundary. (5 to 15 inches, (13 to 38 cm) thick)
2Bt3--17 to 23 inches, (43 to 58 cm); yellow (10YR 7/6) very gravelly loam, yellowish brown (10YR 5/6) moist; 22 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; few fine to coarse roots; common very fine and few medium tubular pores; few distinct discontinuous clay films in pores; 40 percent gravel and 15 percent cobbles; strongly acid, pH 5.3 by Hellige-Truog; NaF pH 9.6; gradual smooth boundary.
2Bt4--23 to 34 inches, (58 to 86 cm); very pale brown (10YR 7/4) extremely cobbly loam, yellowish brown (10YR 5/6) moist; 18 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine to coarse roots; common very fine and few medium tubular pores; few distinct discontinuous clay films in pores; 30 percent gravel, 40 percent cobbles and 5 percent stones; strongly acid, pH 5.2 by Hellige-Truog; NaF pH 9.4; gradual wavy boundary.
2BCt1--34 to 49 inches, (86 to 124 cm); light red (2.5YR 7/6) extremely cobbly loam, reddish brown (2.5YR 5/4) moist; 16 percent clay; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine to coarse roots; common very fine tubular pores; few distinct discontinuous clay films in pores; 10 percent gravel, 50 percent cobbles and 5 percent stones; strongly acid, pH 5.2 by Hellige-Truog; NaF pH 9.3; gradual wavy boundary. (Combined thickness of the 2Bt3, 2Bt4 and Bt5 horizon is 26 to 71 inches, (66 to 180 cm) thick).
2BCt2--49 to 64 inches, (124 to 163 cm); light reddish brown (2.5YR 7/4) extremely stony loam, light reddish brown (2.5YR 6/4) moist; 16 percent clay; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common fine and medium tubular pores; few distinct discontinuous clay films in root channels and/or pores; 10 percent cobbles and 50 percent stones; strongly acid, pH 5.2 by Hellige-Truog; NaF pH 9.2; gradual wavy boundary. (0 to 15 inches, (0 to 38 cm) thick)
2C--64 to 86 inches, (163 to 218 cm); pink (2.5YR 8/3) very stony loam, light red (2.5YR 7/6) moist; 9 percent clay; massive; slightly hard, friable, slightly sticky and slightly plastic; 10 percent cobbles and 30 percent stones; strongly acid, pH 5.2 by Hellige-Truog; NaF pH 9.3. (0 to 22 inches, (0 to 56 cm) thick)
TYPE LOCATION: Plumas County, California; about 2 miles east of Camel Peak Lookout, approximately 300 feet west and 2550 feet south of the northeast corner of Section 34, Township 22 N., Range 8 E., 39 degrees, 43 minutes, 22.5 seconds North latitude and 121 degrees, 3 minutes, 55.8 seconds West longitude, NAD83. - U.S.G.S. Quad: American House, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock is greater than 60 inches, (152 cm). The mean annual soil temperature is 40 to 47 degrees F, (4 to 8 degrees C). The soil moisture control section is dry in all parts from about August to about October (about 60 days). The particle-size control section averages 20 to 23 percent clay and 41 to 58 percent rock fragments, mostly gravel and cobbles. Mineralogy is mixed. Organic matter ranges from 8 to 17 percent to a depth of 10 inches, (25 cm), 2 to 5 percent from 10 to 23 inches, (25 to 58 cm), 1 to 2 percent from 23 to 64 inches, (58 to 163 cm) and is less than 1 percent from 64 to 85 inches, (163 to 216 cm). Base saturation by sum of cations ranges from 10 to 25 percent from 0.5 to 17 inches, (1.27 to 43 cm) and is less than 10 percent from 17 to 85 inches, (43 to 216 cm). Rock fragments on the surface range from 0 to 5 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones and 0 to 5 percent boulders. Some pedons lack a BCt and or a C horizon.
The A horizon dry color is 7.5YR 4/2, 4/3, 5/3, 5/4, 6/4 or 10YR 4/3. Moist color is 7.5YR 3/2, 3/3, 4/3, 4/4, 5YR 2/2 or 3/2. Texture is loam, sandy loam, gravelly sandy loam, very gravelly sandy loam or cobbly sandy loam. Clay content ranges from 8 to 18 percent. Rock fragments range from 5 to 35 percent gravel and 0 to 15 percent cobbles. NaF pH ranges from 10.5 to 11.5. Acid oxalate extractable Al plus 0.5 Fe ranges from 1.4 to 2.0. P retention ranges from 80 to 85. Glass ranges from 5 to 10 percent. Reaction ranges from slightly acid to strongly acid.
The Bt horizon dry color is 7.5YR 5/3, 5/4, 6/3, 6/4, 7/4 or 7/6. Moist color is 7.5YR 3/2, 3/3, 3/4, 4/2, 4/3, 4/4, 5/3, 5/6 or 5YR 4/4. Texture is gravelly loam, gravelly sandy loam, very gravelly loam, very gravelly fine sandy loam or very gravelly sandy loam. Clay content ranges from 10 to 25 percent. Rock fragments range from 10 to 40 percent gravel and 0 to 15 percent cobbles. NaF pH ranges from 10.5 to 11.5. Acid oxalate extractable Al plus 0.5 Fe ranges from 1.0 to 1.8. P retention ranges from 65 to 85. Glass ranges from 2 to 10 percent. Reaction ranges from slightly acid to strongly acid.
The 2Bt horizon dry color is 7.5YR 5/4, 5/6, 6/4, 6/6, 7/4, 7/6, 5YR 4/6, 5/4, 5/6, 2.5YR 7/6, 10YR 6/4, 7/4, 7/6 or 8/4. Moist color is 7.5YR 3/4, 4/3, 4/4, 5/4, 5/6, 5/8, 6/6, 5YR 4/6, 5/4, 10YR 4/3, 5/6, 6/6 or 7/6. Texture is very gravelly loam, very gravelly sandy loam, very gravelly fine sandy loam, very gravelly sandy clay loam, extremely gravelly loam, extremely gravelly coarse sandy loam, extremely gravelly sandy clay loam, very cobbly loam, very cobbly sandy clay loam, very cobbly clay loam, extremely cobbly loam, extremely cobbly sandy clay loam, very stony loam or very stony clay loam. Clay content ranges from 15 to 32 percent. Rock fragments range from 10 to 70 percent gravel, 5 to 50 percent cobbles, and 0 to 30 percent stones. NaF pH ranges from 9.3 to 10.5. Acid oxalate extractable Al plus 0.5 Fe is less than 1. P retention is less than 60. Reaction ranges from slightly acid to very strongly acid.
The 2BCt horizon dry color is 7.5YR 8/6, 2.5YR 7/4, 10YR 7/4, 7/6, 2.5Y 6/2, 8/1, 8/3 or 8/4. Moist color is 7.5YR 5/6, 6/3, 2.5YR 6/4, 10YR 6/6, 2.5Y 6/6, 7/3, 7/4 or 7/6. Texture is very stony loam, extremely cobbly loam, extremely stony loam or extremely gravelly coarse sandy loam. Clay content ranges from 12 to 18 percent. Rock fragments range from 0 to 80 percent gravel, 5 to 50 percent cobbles and 5 to 50 percent stones. NaF pH ranges from 9.0 to 9.5. Reaction ranges from moderately acid to very strongly acid.
The 2C horizon dry color is 2.5YR 8/3 or 10YR 7/6. Moist color is 2.5YR 7/6 or 10YR 5/6. Texture is very stony loam, extremely gravelly coarse sandy loam, extremely gravelly sandy loam or very gravelly fine sandy loam. Clay content ranges from 9 to 15 percent. Rock fragments range from 0 to 80 percent gravel, 5 to 10 percent cobbles and 30 to 50 percent stones. NaF pH ranges from 9.0 to 9.5. Reaction ranges from moderately acid to very strongly acid.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Stagpoint soils are on ridge tops and side slopes on metamorphic Sierra Nevada mountains. Slopes range from 2 to 70 percent. These soils formed in tephra influenced colluvium and residuum from metamorphic rocks such as metadiorite, metatuff, metadacite, phyllite, quartzite or sodarhyolite. Elevation is 4800 to 5900 feet, (1463 to 1798 m). Mean annual precipitation is 75 to 80 inches, (1905 to 2032 mm). The mean annual temperature is 48 to 50 degrees F, (9 to 10 degrees C). Frost free season is 80 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonepile, Dejonah, Obskel, Obstruction and Powderhouse soils. Bonepile soils are on volcanic ridges, are deep to paralithic contact, are medial over loamy-skeletal and are mesic. Dejonah soils are very deep to paralithic contact and are fine-loamy. Obskel soils are deep to a paralithic contact, are loamy-skeletal and are mesic. Obstruction soils are mesic. Powderhouse soils are moderately deep to paralithic contact of andesitic mudflow, and are medial-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; low to medium runoff; moderately rapid saturated hydraulic conductivity in the A horizon, moderate to moderately rapid in the Bt and 2Bt3 horizons, moderate in the 2Bt4 and 2BCt1 horizons, moderate to moderately rapid in the 2BCt2 horizon and moderately rapid in the 2C horizon.
USE AND VEGETATION: This soil is used for timber production, watershed and wildlife habitat. Vegetation is mainly white fir and California red fir with sugar pine, ponderosa pine, incense cedar and minor amounts of Douglas-fir and California black oak and an understory of Sierra chinquapin, whitethorn ceanothus, greenleaf manzanita, bittercherry, pinemat manzanita, deerbrush, Sierra gooseberry, huckleberry oak, brackenfern, common snowberry, California needlegrass, princes pine, Pacific dogwood and whitevein shinleaf.
DISTRIBUTION AND EXTENT: Plumas and Butte Counties, California. MLRA 22A Sierra Nevada Range. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Plumas County, California 2005. Source of name from Stag Point, Dogwood Peak Quadrangle.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 0.5 to 10 inches, (1.27 to 25 cm) (A, Bt1)
Argillic horizon - zone from 10 to 34 inches, (25 to 86 cm) (Bt2, 2Bt3, 2Bt4).
Andic materials- zone from 0.5 to 17 inches, (1.27 to 43 cm) (A, Bt1, Bt2).
Particle-size control section - zone from 10 to 30 inches, (25 to 76 cm).
The soil moisture control section - zone from 10 to 42 inches, (25 to 107 cm).
Bulk density is assumed to be 1 or less from 0.5 to 16 inches, (1.27 to 41 cm).
ADDITIONAL DATA: Reference samples from lab pedon number: 98P0287 NSSL, Lincoln, NE.