Carrierlytics County Coverage Guide

Marshall County, SD Cell Phone Coverage Map & Network Rankings (2026)

Find the best cell phone network and plan to use in Marshall County, SD.

Using FCC mobile coverage data across cities and ZIP codes in Marshall County, SD, Carrierlytics compares the top-performing networks and the cheapest plans that use them.

Marshall County, SD

Cell phone coverage map for Marshall County, SD

Zoom in for local detail. Tap or click a colored area to see coverage and signal details. On mobile, use two fingers to move the map.

Coverage Key
Less covered More covered
Darker areas mean the carrier covers more of that location.

Map data © OpenStreetMap contributors, © CARTO. Rendered with MapLibre. FCC BDC mobile coverage processed by Carrierlytics.

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Cell phone coverage rankings by network in Marshall County, SD

#1

T-Mobile

Coverage Score 80.8
In Marshall County, SD
Overall
86.5%
4G LTE
86.1% avg. -94 dBm 4G LTE signal where 4G LTE coverage exists: avg. -94 dBm
5G
78.6% avg. -91 dBm 5G signal where 5G coverage exists: avg. -91 dBm
Fast 5G
56.1% avg. -87 dBm Fast 5G signal where Fast 5G coverage exists: avg. -87 dBm
#2

AT&T

Coverage Score 73.8
In Marshall County, SD
Overall
97.6%
4G LTE
97.6% avg. -107 dBm 4G LTE signal where 4G LTE coverage exists: avg. -107 dBm
5G
86.6% avg. -113 dBm 5G signal where 5G coverage exists: avg. -113 dBm
Fast 5G
65.5% avg. -113 dBm Fast 5G signal where Fast 5G coverage exists: avg. -113 dBm
#3

Verizon

Coverage Score 64.0
In Marshall County, SD
Overall
98.7%
4G LTE
98.7% avg. -92 dBm 4G LTE signal where 4G LTE coverage exists: avg. -92 dBm
5G
28.1% avg. -96 dBm 5G signal where 5G coverage exists: avg. -96 dBm
Fast 5G
12.2% avg. -90 dBm Fast 5G signal where Fast 5G coverage exists: avg. -90 dBm
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Coverage by city in Marshall County, SD

Cities and towns are shown for county-level comparison. Coverage percentages use land-area only coverage.

City Verizon AT&T T-Mobile
Amherst, SD 100.0% 100.0% 80.3% 19.9% 100.0% 100.0% 99.9% 36.7% 100.0% 100.0% 99.1% 84.1%
Britton, SD 100.0% 100.0% 100.0% 86.7% 100.0% 100.0% 100.0% 93.3% 100.0% 100.0% 100.0% 100.0%
Clear Lake, SD 100.0% 100.0% 0.0% 0.0% 100.0% 100.0% 70.8% 66.7% 100.0% 100.0% 100.0% 91.7%
Eden, SD 100.0% 100.0% 0.0% 0.0% 75.0% 75.0% 0.0% 0.0% 50.0% 50.0% 25.0% 0.0%
Kidder, SD 100.0% 100.0% 60.0% 60.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 60.0%
Lake City, SD 100.0% 100.0% 0.0% 0.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0%
Langford, SD 100.0% 100.0% 0.0% 0.0% 100.0% 100.0% 83.3% 83.3% 100.0% 100.0% 66.7% 16.7%
Newport Colony, SD 100.0% 100.0% 33.3% 0.0% 100.0% 100.0% 66.7% 0.0% 100.0% 100.0% 50.0% 0.0%
Sunset Colony, SD 100.0% 100.0% 52.2% 0.0% 100.0% 100.0% 100.0% 69.6% 100.0% 100.0% 100.0% 100.0%
Veblen, SD 100.0% 100.0% 0.0% 0.0% 100.0% 100.0% 100.0% 100.0% N/A N/A N/A N/A
Westwood Colony, SD 100.0% 100.0% 68.0% 16.0% 100.0% 100.0% 100.0% 20.0% 100.0% 100.0% 100.0% 76.0%

About The Coverage Data

Coverage and signal estimates are derived by Carrierlytics from carrier-reported data in the FCC’s National Broadband Coverage Map, last updated in June 2025. “Percent covered” shows how much of the city or ZIP code area has a carrier signal, whether weak or strong. Signal bars show the estimated average signal strength in areas of Marshall County, SD where that carrier has coverage.

If a carrier says you should have service but you do not, run a challenge test with the FCC Mobile Speed Test App. The FCC uses those results to check carrier-submitted coverage data and requires a carrier response when enough tests show a pattern of inaccurate coverage reporting.