Utah: 29 counties covered
Of 29 rated Utah counties, 7 are in EPA's highest radon-potential zone (Zone 1) — but every county page links to testing guidance regardless of zone, because a county rating is a county-wide average, not a reading for any one house.
- Salt Lake County
- Utah County
- Davis County
- Weber County
- Washington County
- Cache County
- Tooele County
- Iron County
- Box Elder County
- Summit County
- Uintah County
- Wasatch County
- Sanpete County
- Sevier County
- Duchesne County
- Carbon County
- San Juan County
- Millard County
- Juab County
- Morgan County
- Emery County
- Grand County
- Kane County
- Beaver County
- Garfield County
- Rich County
- Wayne County
- Piute County
- Daggett County