Soil Series Atlas

Threebear soil series

Medial over loamy, amorphic over mixed, superactive, frigid Oxyaquic Udivitrands

050100150cm1 ft2 ft3 ft4 ft5 ftOiOrganic layer · slightly decomposed0–3 cm · 0–1 inATopsoil3–8 cm · 1–3 inBw1Subsoil · color or structure change8–25 cm · 3–10 inBw2Subsoil · color or structure change25–46 cm · 10–18 in2E/BtMixed leached layer and subsoil · claybuild-up, different parent material46–66 cm · 18–26 in2Bt/E1Mixed subsoil and leached layer · claybuild-up, different parent material66–89 cm · 26–35 in2Bt/E2Mixed subsoil and leached layer · claybuild-up, different parent material89–102 cm · 35–40 in2Btxb1Subsoil · clay build-up, fragipan: denseand brittle, buried, different parentmaterial102–140 cm · 40–55 in2Btxb2Subsoil · clay build-up, fragipan: denseand brittle, buried, different parentmaterial140–175 cm · 55–69 in050100150cmOiOrganic layer ·slightly decomposed0–3 cm · 0–1 inATopsoil3–8 cm · 1–3 inBw1Subsoil · color orstructure change8–25 cm · 3–10 inBw2Subsoil · color orstructure change25–46 cm · 10–18 in2E/BtMixed leached layer andsubsoil · claybuild-up, differentparent material46–66 cm · 18–26 in2Bt/E1Mixed subsoil andleached layer · claybuild-up, differentparent material66–89 cm · 26–35 in2Bt/E2Mixed subsoil andleached layer · claybuild-up, differentparent material89–102 cm · 35–40 in2Btxb1Subsoil · claybuild-up, fragipan:dense and brittle,buried, differentparent material102–140 cm · 40–55 in2Btxb2Subsoil · claybuild-up, fragipan:dense and brittle,buried, differentparent material140–175 cm · 55–69 in
Typical pedon, to scale: 175 cm (69 in), 9 horizons.

Andisols — soils formed in volcanic ash and similar material

Nationally Threebear is a small series: 55,841 acres, 5,461st of 24,791 by area. Established in 2003, it is the newest series in the atlas. It is the only series in the atlas that falls in the medial over loamy particle-size class. Every mapped acre is in Idaho. It is the state soil of Idaho.

Depth
Moderately deep
Drainage
Moderately well drained

Compare with another seriesSimilar series in the finder

Where Threebear is mapped

55,841 acres in 5 soil survey areas, from current SSURGO data.

AlabamaArizonaColoradoFloridaGeorgiaIndianaKansasMaineMassachusettsMinnesotaNew JerseyNorth CarolinaNorth DakotaOklahomaPennsylvaniaSouth DakotaTexasWyomingConnecticutMissouriWest VirginiaIllinoisNew MexicoArkansasCaliforniaDelawareDistrict of ColumbiaIowaKentuckyMarylandMichiganMississippiMontanaNew HampshireNew YorkOhioOregonTennesseeUtahVirginiaWashingtonWisconsinNebraskaSouth CarolinaIdaho: 55,841 acresNevadaVermontLouisianaRhode Island

Share of all Threebear acres

  1. Idaho100%
  • Rank in the state · share of its mapped soil
  • Idaho 112th of 1,806 · 0.20%

In the field

Drainage

Moderately well drained

Drains fastStays wet

Soil depth

Moderately deep

ShallowDeep
Parent material
Loess, volcanic ash/tephra
Landform
Mountains, benches, hills, plateaus/tablelands
Major land resource areas
43A
Type location
Idaho

How it is classified

  1. OrderAndisols
  2. SuborderVitrands
  3. Great groupUdivitrands
  4. SubgroupOxyaquic Udivitrands
  5. FamilyMedial over loamy, amorphic over mixed, superactive, frigid Oxyaquic Udivitrandsmedial over loamy particle-size classamorphic over mixed mineralogy classsuperactive cation-exchange activity classfrigid soil temperature regime

Against other Andisols

Threebear makes up 0.27% of all mapped Andisols — the 83rd largest of 1,093 series in the order.

Solum thickness (topsoil + subsoil)

175 cm over a median of 105 cm

Depth to the subsoil

8 cm under a median of 20 cm

Depth described

175 cm over a median of 152 cm

Its relatives

Other Andisols in this atlas

  1. Threebear175 cm · Oxyaquic Udivitrands
  2. Tokul157 cm · Aquic Vitrixerands
  3. Hilo150 cm · Acrudoxic Hydrudands

Horizon by horizon

HorizonLayerDepthThickness
OiOrganic layer: slightly decomposed0–3 cm0–1 in3 cm
ATopsoil3–8 cm1–3 in5 cm
Bw1Subsoil: color or structure change8–25 cm3–10 in17 cm
Bw2Subsoil: color or structure change25–46 cm10–18 in21 cm
2E/BtMixed leached layer and subsoil: clay build-up, different parent material46–66 cm18–26 in20 cm
2Bt/E1Mixed subsoil and leached layer: clay build-up, different parent material66–89 cm26–35 in23 cm
2Bt/E2Mixed subsoil and leached layer: clay build-up, different parent material89–102 cm35–40 in13 cm
2Btxb1Subsoil: clay build-up, fragipan: dense and brittle, buried, different parent material102–140 cm40–55 in38 cm
2Btxb2Subsoil: clay build-up, fragipan: dense and brittle, buried, different parent material140–175 cm55–69 in35 cm

Sources: USDA–NRCS Official Series Description (revised 2013-07), Soil Classification database and SSURGO. Ranks computed by Soil Series Atlas. Method · Guides