Arizona Soil Surveys
Arizona has 51 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Aridisols — dry-climate soils with limited organic matter and often calcium carbonate accumulation, making up roughly 43% of surveyed soils. Entisols — young soils with little profile development, often on floodplains or steep slopes account for another 32%.
In terms of drainage, 78% of Arizona soils are classified as well drained. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.
Soil Types
Aridisols
43% of surveyed soils
Dry-climate soils with low organic matter. Often have caliche layers that make excavation difficult. Low shrink-swell is good for foundations.
Entisols
32% of surveyed soils
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.
Mollisols
15% of surveyed soils
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Alfisols
5% of surveyed soils
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Vertisols
1% of surveyed soils
High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.
Inceptisols
1% of surveyed soils
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Survey Areas
Aguila-Carefree Area, Arizona, Parts of Maricopa and Pinal CountiesApache County, Arizona, Central PartApache-Sitgreaves National Forests, Arizona, Parts of Apache, Coconino, Greenlee, and Navajo CountiesBeaver Creek Area, ArizonaBlack Hills-Sedona Area, Arizona, Parts of Coconino and Yavapai CountiesCabeza Prieta Area, Arizona, Parts of Pima and Yuma CountiesCanyon de Chelly National Monument, ArizonaChinle Area, Parts of Apache and Navajo Counties, Arizona, and San Juan County, New MexicoCochise County, Arizona, Douglas-Tombstone PartCochise County, Arizona, Northwestern PartCoconino County Area, Arizona, Central PartCoconino County Area, Arizona, North Kaibab PartColorado River Indian Reservation, Parts of La Paz County, Arizona, and Riverside and San Bernardino Counties, CaliforniaCoronado National Forest, Arizona, Parts of Cochise, Graham, Pima and Pinal CountiesEastern Maricopa and Northern Pinal Counties Area, ArizonaEastern Pinal and Southern Gila Counties, ArizonaFort Apache Indian Reservation, Arizona, Parts of Apache, Gila, and Navajo CountiesFort Defiance Area, Parts of Apache and Navajo Counties, Arizona and McKinley and San Juan Counties, New MexicoGila Bend-Ajo Area, Arizona, Parts of Maricopa and Pima CountiesGila River Indian Reservation, Arizona, Parts of Maricopa and Pinal CountiesGila-Duncan Area, Parts of Graham and Greenlee Counties, ArizonaGraham County, Arizona, Southwestern PartGrand Canyon Area, Arizona, Parts of Coconino and Mohave CountiesHopi Area, Arizona, Parts of Coconino and Navajo CountiesHualapai-Havasupai Area, Arizona, Parts of Coconino, Mohave, and Yavapai CountiesKaibab National Forests, Arizona, Parts of Coconino, Mohave and Yavapai CountiesKofa Area, Arizona, Parts of La Paz and Yuma CountiesLittle Colorado River Area, Arizona, Parts of Coconino and Navajo CountiesLong Valley Area, ArizonaLuke Air Force Range, Arizona, Parts of Maricopa, Pima and Yuma CountiesMaricopa County, Arizona, Central PartMohave County Area, Arizona, Northeastern Part, and Part of Coconino CountyMohave County, Arizona, Central PartMohave County, Arizona, Southern PartNavajo County Area, Arizona, Central PartNavajo Mountain Area, Arizona, Parts of Apache, Coconino and Navajo CountiesOak Creek-San Francisco Peaks Area, Arizona, Part of Coconino CountyOrgan Pipe Cactus National Monument, ArizonaPima County, Arizona, Eastern PartPinal County, Arizona, Western PartSafford Area, ArizonaSan Carlos Indian Reservation, Arizona, Parts of Gila and Graham CountiesSan Simon Area Parts of Cochise Graham and Greenlee Counties, ArizonaSanta Cruz and Parts of Cochise and Pima Counties, ArizonaShivwits Area, Arizona, Part of Mohave CountyTohono O'Odham Nation, Arizona, Parts of Maricopa, Pima and Pinal CountiesTonto National Forest, Arizona, Parts of Gila, Maricopa, Pinal and Yavapai CountiesTucson-Avra Valley Area, ArizonaWillcox Area, Arizona Parts of Cochise and Graham CountiesYavapai County, Arizona, Western PartYuma-Wellton Area, Parts of Yuma County, Arizona and Imperial County, California