Daniels County, MT: the USDA septic-suitability picture
Very limited
USDA puts Daniels County, MT at "Very limited" for septic absorption fields, the dominant reading across 83.8% of the county's soil. A standard gravity system routinely fails on ground like this; the same share of the county falls in USDA's worst absorption-field bucket outright. For scale: 1,426.27 square miles and 1,625 people call Daniels County home.
Before you rely on this for one lot
This is a countywide, area-weighted figure across every soil survey map unit in Daniels County, MT - never a reading for one specific parcel. The real answer for one lot is still a site-specific perc test, running about $750-$1,850 (typically near $1,300).
Budgeting for a system in Daniels County, MT
Daniels County's soil reading pushes the likely outcome toward an engineered system rather than a conventional one. Conventional systems run $3,000-$8,000 where they pass; where they don't, engineered alternatives (mound or aerobic treatment, whichever the health department requires) run $10,000-$40,000 - budget toward the higher figure until a perc test says otherwise.
Where this sits nationally
Among the 3,058 rated counties on this site, Daniels County, MT ranks 1,805 most-constrained nationally, and 18 of 54 within Montana.
Related guides
How this rating is built, and its real limits · Conventional vs. engineered septic systems