LOCATION BOILER OR

Established Series
Rev. MHF-TDT-KLS
05/2023

BOILER SERIES

The Boiler series consists of deep, well drained soils on forested mountains. They formed in colluvium from tuffaceous sediments. Slopes are 35 to 60 percent. The mean annual precipitation is about 610 mm, and the mean annual air temperature is about 6 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Ultic Palexerolls

TYPICAL PEDON: Boiler gravelly loam - on a 55 percent convex northeast-facing slope, woodland. (Colors are for moist soil unless otherwise noted.)

Oe--0 to 3 cm; partially decomposed litter layer of twigs, needles, and leaves.

A1--3 to 18 cm; very dark grayish brown (10YR3/2) gravelly loam, grayish brown (10YR5/2) dry; weak very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many very fine and fine tubular pores; 25 percent gravel and 5 percent cobbles; slightly acid (pH 6.4); clear smooth boundary.

A2--18 to 36 cm; dark brown (10YR3/3) very gravelly clay loam, brown (10YR5/3) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many very fine and fine random tubular pores; 40 percent gravel and 5 percent cobbles; neutral (pH 6.6); abrupt smooth boundary. (Combined thickness of A1 and A2 - 25 to 50 cm)

2Bt1--36 to 66 cm; brown (10YR4/3) extremely gravelly silty clay, brown (10YR5/3) dry; moderate fine and medium subangular blocky structure; hard, firm, sticky and plastic; common fine and few medium roots; common very fine and fine tubular pores; common moderately thick clay films on ped faces and lining pores; 60 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (25 to 64 cm thick)

3Bt2--66 to 127 cm; dark yellowish brown (10YR4/4) extremely gravelly clay, yellowish brown (10YR5/4) dry; strong medium prismatic structure; very hard, very firm, very sticky and very plastic; no roots; common very fine tubular pores; many thick clay films on ped faces and lining pores; 60 percent gravel and 5 percent cobbles; neutral (pH 6.8). (0 to 64 cm thick)

4Cr--127 cm; weathered sediments.

TYPE LOCATION: Baker County, Oregon; NE1/4, NE1/4, SW1/4, NE1/4 of sec. 25, T. 11 S., R. 36 E.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 8 degrees C
The soils are usually moist but are dry between depths of 10 and 30 cm for 60 to 80 consecutive days during the summer.
Thickness of mollic epipedon--25 to 50 cm
Depth to 2Bt horizon--25 to 50 cm
Depth to paralithic contact--more than 100 cm

Particle-size control section:
Rock fragment content--35 to 70 percent
Reaction-pH 6.1 to 7.3

A horizon
Value--2 or 3 moist, 3 through 5 dry
Chroma--1 through 3, moist or dry
Rock fragment content--15 to 30 percent total; 15 to 25 percent gravel and 0 to 5 percent cobbles or stones

2Bt horizon
Value--3 or 4 moist, 4 or 5 dry
Chroma--3 or 4 moist and dry
Texture--silty clay or clay
Clay content--50 to 60 percent
Rock fragment content--35 to 70 percent total; 35 to 60 percent gravel and 0 to 10 percent cobbles
Structure--moderate or strong angular or subangular blocky, and in some pedons grades into moderate or strong prismatic

3Bt horizon, when present
Value--3 or 4 moist, 4 or 5 dry
Chroma--3 or 4 moist and dry
Rock fragment content--35 to 70 percent total; 35 to 60 percent gravel and 0 to 10 percent cobbles
Structure--coarse angular blocky or medium to coarse prismatic

COMPETING SERIES: These are the Hudspeth and Player series. Hudspeth soils are 50 to 100 cm deep to bedrock and are mapped on adjacent south slopes. Player soils are more than
150 cm deep to bedrock and are usually dry for more than 90 consecutive days following the summer solstice.

GEOGRAPHIC SETTING:
Landform--side slopes of forested mountains
Elevation--1225 to 1525 meters
Slopes--35 to 60 percent
Parent material--colluvium from tuffaceous sediments
Mean annual precipitation--410 to 760 mm
Mean annual air temperature--4 to 7 degrees C
Frost-free period--30 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is rapid. Permeability is slow.

USE AND VEGETATION: These soils are used mainly for timber production. The vegetation is mainly ponderosa pine, Douglas-fir, common snowberry, wax currant, spirea, serviceberry, elk sedge, pinegrass, some Idaho fescue, heartleaf arnica and wild strawberry.

DISTRIBUTION AND EXTENT: Boiler soils are of small extent in the mountainous areas of eastern Oregon; MLRA 43C.

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

SERIES ESTABLISHED: Baker County Area, Oregon; 1988.

REMARKS: Diagnostic horizons and features in this pedon are:
Mollic epipedon--3 to 36 cm (A horizon)
Argillic horizon--36 to 127 cm (2Bt1, 3Bt2 horizons)
"Pale" feature--argillic horizon with clayey particle-size class and abrupt upper boundary (2Bt1 horizon)
Ultic feature--base saturation of between 60 and 75 percent either throughout the entire argillic horizon or in the upper 50 cm of the argillic horizon, whichever is thinner.

Particle-size control section--36 to 86 cm (all of the 2Bt1 horizon and part of the 3Bt2 horizon)

Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 05/2023

National Cooperative Soil Survey
U.S.A.