Across the United States, 69.8% of area has 4G LTE from at least one of AT&T, T-Mobile or Verizon, on filings to the FCC as of December 31, 2025. County by county that average breaks apart: in Pocahontas County, WV the figure is 15.8%.
These are the twenty counties with the smallest share of land covered by any carrier. Counties that are more than a fifth water are left out: the FCC's area figures include lakes and coastal water, carriers file it inconsistently, and a county that is mostly sea would otherwise top the list on geography rather than on any failure to build a network.
The twenty least-covered counties
Any-carrier 4G first, then each carrier's own outdoor figure, the water share, and the carrier that leads where one clearly does.
| County | 4G, any carrier | AT&T | T-Mobile | Verizon | Water | Leader |
|---|---|---|---|---|---|---|
| Pocahontas County, WV | 15.8% | 16.5% | 4.8% | 2.7% | 0.2% | AT&T |
| Idaho County, ID | 16.3% | 11.2% | 9.2% | 13.2% | 0.3% | Low from all three |
| Clearwater County, ID | 20.1% | 7.5% | 13.1% | 10.9% | 1.2% | Low from all three |
| Lincoln County, MT | 21.2% | 16.5% | 15.1% | 14.2% | 1.7% | Low from all three |
| Custer County, ID | 22.2% | 10.4% | 6.2% | 0% | 0.3% | AT&T (T-Mobile close behind) |
| Shoshone County, ID | 22.2% | 12.8% | 12.8% | 14.8% | 0.2% | Low from all three |
| Highland County, VA | 22.8% | 10% | 7.4% | 21.5% | 0.2% | Verizon |
| San Juan County, CO | 24.1% | 13% | 13.5% | 22.4% | 0.2% | Verizon |
| Valley County, ID | 26.4% | 18% | 14.6% | 25.9% | 1.8% | Verizon |
| Webster County, WV | 26.7% | 22.5% | 14.1% | 1.9% | 0.5% | AT&T |
| Pendleton County, WV | 27.2% | 19.7% | 12.6% | 2.1% | 0.3% | AT&T |
| Piscataquis County, ME | 27.3% | 8.8% | 13.2% | 25.1% | 9.5% | Verizon (T-Mobile close behind) |
| Pitkin County, CO | 27.4% | 23.2% | 15.6% | 19.3% | 0.3% | AT&T (Verizon close behind) |
| Wallowa County, OR | 30.7% | 24% | 16.2% | 22.1% | 0.2% | AT&T (Verizon close behind) |
| Skamania County, WA | 31.1% | 22.2% | 15.4% | 13.9% | 1.7% | AT&T |
| Meagher County, MT | 32.1% | 19.3% | 26.8% | 22.4% | 0.1% | T-Mobile (Verizon close behind) |
| Gunnison County, CO | 33% | 24.7% | 15.8% | 24% | 0.6% | AT&T (Verizon close behind) |
| Flathead County, MT | 33.4% | 25.4% | 26.1% | 28.1% | 3.2% | Tie (within 5 points) |
| Lemhi County, ID | 34.4% | 25.5% | 21.6% | 17.5% | 0.1% | AT&T (T-Mobile close behind) |
| Brewster County, TX | 34.4% | 24.9% | 16.8% | 22.7% | 0.1% | AT&T (Verizon close behind) |
Source: FCC National Broadband Map, carrier filings as of December 31, 2025. Share of area where each carrier reports 4G LTE or 5G to a phone outdoors. Carrier-reported, not measured.
Why a county can be this empty
Almost every county on this list is mountain or forest: terrain that blocks signal, few people to justify a mast, and long distances between the towns that do have one. Coverage in the county seat is usually far better than the county-wide share suggests.
The figures are shares of land area, not of people. A county can be 80% uncovered and still have a signal everywhere anyone actually lives.
What to do if you live in or travel through one
Compare the three carriers on the county's own numbers above rather than on national advertising: the leader nationally is often not the leader here.
If you drive through, check the in-car figure as well as the outdoor one on your state page -- in-car coverage is always the smaller of the two, and in this terrain the gap is at its widest.