LOCATION LAPOETCREEK             WA

Tentative Series
IRD. AJF/MGR/MPR
01/2025

LAPOETCREEK SERIES

Landscape--river valley
Landform--terrace
Slope--0 to 15 percent
Parent material--alluvium
Mean annual precipitation--about 2500 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime-- udic
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Coarse-loamy, mixed, active, frigid Typic Dystrudepts

TYPICAL PEDON: Lapoetcreek loam on alluvial terrace with slope of 1 percent and elevation of 460 m. (The soil was moist throughout when described.)

A--0 to 9 cm; very dark gray (10YR 3/1) dry, black (10YR 2/1) loam; weak fine granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine and fine roots, and common medium and coarse roots; many fine irregular pores; very strongly acid (pH 4.6); clear wavy boundary

Bw1--9 to 41 cm; very dark gray (10YR 3/1) dry, black (10YR 2/1) sandy loam; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; many very fine and fine roots, and few medium roots; common very fine irregular and tubular pores; very strongly acid (pH 4.7); gradual wavy boundary

Bw2--41 to 76 cm; very dark gray (2.5Y 3/1) dry, black (2.5Y 2.5/1) loam; weak very fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; many very fine, and common fine and medium roots; many very fine and fine irregular pores; very strongly acid (pH 4.8); clear smooth boundary

Bw3--76 to 150 cm; very dark gray (2.5Y 3/1) dry, black (2.5Y 2.5/1) sandy loam; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; common very fine and fine roots; common very fine irregular and tubular pores; very strongly acid (pH 5.0)

TYPE LOCATION: Olympic National Park, Jefferson County, Washington, East of Six Ridge Trail about one quarter mile from the junction with Skokomish River Trail.
Latitude--47.570028
Longitude-- -123.377211
Datum-WGS84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--5 to 8 degrees C
Mean summer soil temperature--6 to 10 degrees C

Particle size control section
*Clay content--5 to 15 percent
*Gravel content--0 to 15 percent

A horizon
Hue--10YR or 2.5Y
Value-- 2.5 to 3 dry or moist
Chroma--1 or 2 dry or moist
Fine-earth texture--sandy loam, loam
Clay content--5 to 15 percent
Gravel content--0 to 15 percent
Reaction-- 4.5 to 5.5
Thickness--5 to 15 cm

Bw horizons
Hue--10YR or 2.5Y
Value--2.5 to 4 dry or moist
Chroma--1 or 2 dry or moist
Fine-earth texture--sandy loam, loam
Clay content--5 to 15 percent
Gravel content--0 to 15 percent
Reaction--4.5 to 5.5
Combined thickness--135 to 145 cm

COMPETING SERIES:
Bice, Dummerston, Elka, Flatiron, Haights, Lombard-has greater than 15 percent coarse fragments in particle size control section
Millsite, Mongaup--has lithic contact within 100 cm of the soil surface

GEOGRAPHIC SETTING:
Elevation--450 to 1000 m
Climate--warm, dry summers; cool, wet winters
Mean annual precipitation--2000 to 3000 mm
Mean annual air temperature--7 to 11 degrees C
Frost-free period--90 to 150 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Lolocreek--sandy-skeletal particle size class; occurs on similar landforms
Steeplerock--no cambic diagnostic horizon; occurs on terraces with frequent flooding
Mountscott--aquic conditions within 50 cm of the mineral soil surface; occurs on depressions on similar landforms

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class-- well drained
Saturation in normal years--none
Flooding--very rare
Ponding--none
Saturated hydraulic conductivity (Ksat)--high or very high throughout

USE AND VEGETATION:
Use--wildlife habitat, recreation
Potential natural vegetation-Pacific silver fir, western hemlock, oval-leaf huckleberry, salmonberry, western swordfern, three-leaf foamflower, youth on age

DISTRIBUTION AND EXTENT: Olympic Mountains, Washington; MLRA 1; small extent

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

SERIES PROPOSED: Olympic National Park, Jefferson County, Washington 2023; name from Lapoet Creek in Olympic National Park

REMARKS:
Diagnostic horizons and other features in this pedon:
*Particle-size control section--zone from 25 to 100 cm
*Ochric epipedon
*Cambic horizon--zone from 9 to 76 cm

---

National Cooperative Soil Survey
U.S.A.