LOCATION EACHUSTON               CO+MT

Established Series
Rev. AJC/LF/KLS
01/2023

EACHUSTON SERIES

The Eachuston series consists of very deep, poor to very poorly drained, rapidly permeable soils on nearly level to gently sloping flood plains and low terrace. They formed in very gravelly, coarse textured alluvial sediments. Slope ranges from 0 to 6 percent. The mean annual air temperature is about 2 degrees C, and the mean annual precipitation is about 250 mm.

TAXONOMIC CLASS: Sandy-skeletal, mixed Typic Cryaquents

TYPICAL PEDON: Eachuston gravelly loam - grassland. (Colors are for dry soil unless otherwise noted.)

Oi--0 to 8 cm; undecomposed organic material, principally grass remains, roots, and leaves.

A--8 to 18 cm; dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable; 30 percent gravel; neutral (pH 7.0); clear smooth boundary. (8 to 13 cm thick)

AC--18 to 28 cm; grayish brown (10YR 5/2) gravelly loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure that parts to fine granules; soft, very friable; 30 percent gravel; common medium distinct mottles, reddish brown (5YR 4/4) moist; neutral (pH 7.0); clear wavy boundary. (8 to 13 cm thick)

2C--28 to 160 cm; grayish brown (10YR 5/2) very gravelly loamy sand, dark grayish brown (10YR 4/2) moist; common medium distinct reddish brown (5YR 4/4) mottles; 60 percent gravel and some cobbles.

TYPE LOCATION: Jackson County, Colorado; about 645 meters northwest of SE corner of Sec. 20, T. 7 N., R. 77 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 degrees C
Mean summer soil temperature--12 degrees C
Base saturation--80 to 100 percent

Particle-size control section:
Texture--very gravelly loamy sand or sand
Rock fragment content--35 to 80 percent, and are mainly gravel less than 75 mm in diameter

A horizon
Hue--5Y through 7.5 YR
Value--4 through 6 dry, 2 through 4 moist
Chroma--1 or 2 and has common medium distinct to many large prominent mottles
Reaction--pH 6.1 to 7.8
Structure--granular structure but has subangular blocky structure in some pedons

C horizon
Hue--5Y through 7.5YR and has common medium distinct to many large prominent mottles
Reaction--pH 6.1 to 7.8

COMPETING SERIES: These are the Juban, McKinney, and Stave series. Juban soils are calcareous and have fine-loamy over sandy or sandy-skeletal control sections. McKinney soils have a fine-loamy control section. Stave soils have a sandy control section.

GEOGRAPHIC SETTING:
Landform--nearly level to gently sloping flood plains and low terraces
Elevation--2425 to 2800 meters
Slope--0 to 6 percent
Parent material--very gravelly, coarse textured alluvial sediments
Mean annual precipitation--250 mm, with peak periods of precipitation during the spring and early summer
Mean annual air temperature--2 to 3 degrees C
Mean summer air temperature--12 degrees C

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Poor to very poorly drained; slow runoff; rapid permeability. These soils have high water tables that stand at or near the surface of the ground most of the year.

USE AND VEGETATION: These soils are used as native pastureland or as native hay meadow. Principal native vegetation is timothy, sedges, bluegrass, and alsike clover.

DISTRIBUTION AND EXTENT: Eachuston soils are of small extent in the high mountain valleys of northcentral Colorado and western Montana. MLRAs 44B and 48A

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

SERIES ESTABLISHED: Jackson County, Colorado, 1973

REMARKS: Converted to metric and O horizons were updated to start at zero. Competing series section was not updated. 12/2022

---

National Cooperative Soil Survey
U.S.A.