Organ Pipe Cactus National Monument, Arizona
The most common soil here is Gunsight, on about 21% of the land: a very gravelly loam, a balanced mix that crumbles in your hand. Gilman and Lomitas come next.
About all of the land drains well.
USDA rates 39% of the land very limited for a standard septic drain field, and 32% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 22% of the land floods occasionally or more, and bedrock lies within 40 inches under 32% of it.
Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.
The soils you're most likely standing on
The biggest named soils in Organ Pipe Cactus National Monument, Arizona, each drawn five feet deep from its official USDA description, in its recorded colors.
Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.
The biggest mapped areas
The dominant drainage class is Well drained and the dominant hydrologic group is B (moderate infiltration). The most common soil order is Aridisols — dry-climate soils with limited organic matter and often calcium carbonate accumulation. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Organ Pipe Cactus National Monument, Arizona. Search your address to find the exact soil composition, drainage, and series details at your specific location.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Gunsight very gravelly loam, 2 to 15 percent slopes | 58K | Well drained | B | Somewhat limited | Somewhat limited |
| Harqua-Gunsight complex | 34K | Well drained | C | Not limited | Not limited |
| Lomitas extremely stony loam, 8 to 40 percent slopes | 33K | Well drained | D | Very limited | Very limited |
| Rock land | 30K | Well drained | Not rated | Not rated | |
| Gilman very fine sandy loam | 26K | Well drained | B | Very limited | Very limited |
| Rillito gravelly sandy loam | 22K | Well drained | A | Not limited | Not limited |
| Stony land-Rock outcrop association | 22K | Well drained | Not rated | Not rated | |
| Antho fine sandy loam | 15K | Well drained | A | Very limited | Very limited |
| Growler-Antho complex | 14K | Well drained | A | Very limited | Very limited |
| Cherioni gravelly very fine sandy loam, 0 to 8 percent slopes | 13K | Well drained | D | Very limited | Very limited |
| Torrifluvents | 12K | Excessively drained | Not rated | Not rated | |
| Cipriano gravelly loam | 11K | Well drained | D | Not limited | Very limited |
| Gunsight very gravelly loam, 0 to 2 percent slopes | 10K | Well drained | B | Not limited | Somewhat limited |
| Ajo very gravelly loam, 1 to 5 percent slopes | 9K | Well drained | C | Somewhat limited | Very limited |
| Rock outcrop | 6K | Excessively drained | D | Not rated | Not rated |
| Ajo very cobbly sandy loam, 2 to 5 percent slopes | 3K | Well drained | C | Somewhat limited | Very limited |
| Gilman very fine sandy loam, saline | 2K | Well drained | B | Very limited | Very limited |
| Perryville very cobbly fine sandy loam, 0 to 8 percent slopes | 2K | Well drained | B | Not limited | Somewhat limited |
| Laveen loam | 2K | Well drained | B | Not limited | Somewhat limited |
| Gachado extremely cobbly loam, 2 to 8 percent slopes | 2K | Well drained | D | Very limited | Very limited |
Soil Orders in This Area
The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.
What This Means
Building & Foundations
About 32% of soils have significant building limitations, while the rest are generally suitable. Check specific sites carefully — conditions vary across the area.
Septic Systems
About 39% of soils have significant septic limitations, while others are more suitable. A perc test is essential — conditions vary across the area.
Gardening & Agriculture
Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.