Soil Series Atlas

Guides

Short explainers on reading soil series data, each built on numbers counted from the 90 series in this atlas and the national soil survey.

  1. How to read a soil series nameThe name is a place label. The classification next to it, read from right to left, gives the order, suborder, great group, subgroup and family.5 min read
  2. The twelve soil orders, measuredMollisols cover the most mapped ground, Oxisols the least. All twelve orders by area, number of series and typical profile depth.4 min read
  3. Soil drainage classes, countedSeven classes, from excessively to very poorly drained. In this atlas 62 of 90 series are well drained; the wet ones span 7 orders.4 min read
  4. How deep soil series goMost atlas series are very deep (68 of 90), and the median description runs to 168 cm. Depth class and described depth measure different things.4 min read
  5. State soils and where series were established50 of 52 state soils were first described in the state that chose them. Only 8 are the most extensive series in their state.3 min read
  6. Using the soil series finderEight filters, a map of where the matches are mapped and a side-by-side profile comparison. Five searches show what each part returns.4 min read

Written by Ethan Mitchell. Published October 27, 2026. Every figure comes from the USDA–NRCS data described on the data & method page.