Soil Series Atlas

Mollisols

Soils with a thick, dark, organic-rich topsoil

050100150cm1 ft2 ft3 ft4 ftAbove the subsoilTopsoil and any leached layer0–25 cm · 0–10 inSubsoilFirst B horizon to the base of the solum25–104 cm · 10–41 inBelow the solumParent material or rock, to the mediandepth described104–152 cm · 41–60 in050100150cmAbove the subsoilTopsoil and any leachedlayer0–25 cm · 0–10 inSubsoilFirst B horizon to thebase of the solum25–104 cm · 10–41 inBelow the solumParent material orrock, to the mediandepth described104–152 cm · 41–60 in
The typical Mollisols profile: a schematic drawn to scale from the medians of 6,058 official series descriptions. It is not a real pedon.

Soil order · 7,178 established series in the classification database

Mollisols cover 435.60 million acres of mapped U.S. soils — 27.3% of all series acres, the largest of the twelve orders — across 7,593 mapped series.

Median solum thickness in their typical pedons is 104 cm, with the first B horizon at 25 cm. Official descriptions of Mollisols go down a median 152 cm.

Mollisols among the twelve orders

Share of all acres mapped to a named series, with this order highlighted.

Mollisols 27.3% · Alfisols 17.3% · Entisols 12.3% · Ultisols 11.8% · Inceptisols 11.4% · Aridisols 9.7% · Spodosols 3.7% · Vertisols 2.7% · Histosols 1.9% · Andisols 1.3% · Gelisols 0.5% · Oxisols <0.1%

Guide: The twelve soil orders, measured

Largest Mollisols series

Mapped acres in current SSURGO data, across all series in the order.

  1. Williams4,232,753 acres4.2 M
  2. Ector4,014,662 acres4.0 M
  3. Harney3,889,386 acres3.9 M
  4. Pullman3,074,689 acres3.1 M
  5. Tarrant2,936,422 acres2.9 M
  6. Ulysses2,812,965 acres2.8 M
  7. Uly2,808,719 acres2.8 M
  8. Holdrege2,786,821 acres2.8 M
  9. Keith2,760,253 acres2.8 M
  10. Richfield2,581,668 acres2.6 M

Mollisols on this site

19 Mollisols series profiled here, largest first, drawn at one depth scale.

  1. WilliamsTypic Argiustolls · 3 states · state soil
  2. EctorLithic Calciustolls · 2 states
  3. HarneyTypic Argiustolls · 2 states · state soil
  4. PullmanTorrertic Paleustolls · 2 states
  5. TarrantLithic Calciustolls · 2 states
  6. UlyssesTorriorthentic Haplustolls · 6 states
  7. UlyTypic Haplustolls · 3 states
  8. HoldregeTypic Argiustolls · 2 states · state soil
  9. KeithAridic Argiustolls · 5 states
  10. RichfieldAridic Argiustolls · 5 states
  11. CretePachic Udertic Argiustolls · 2 states
  12. EckrantLithic Haplustolls · 1 state
  13. ZahlTypic Calciustolls · 3 states
  14. BarnesCalcic Hapludolls · 3 states
  15. DrummerTypic Endoaquolls · 4 states · state soil
  16. ScobeyAridic Argiustolls · 2 states · state soil
  17. HoudekTypic Argiustolls · 1 state · state soil
  18. TamaTypic Argiudolls · 5 states · state soil
  19. PortCumulic Haplustolls · 3 states · state soil