Carrierlytics City Coverage Guide

Big Arm, MT Cell Phone Coverage Map & Network Rankings (2026)

Don't overpay for a network that struggles where you actually use your phone.

Using FCC mobile coverage data across Big Arm, MT ZIP codes, Carrierlytics compares the top-performing networks and the cheapest plans that use them.



Cell phone coverage map for Big Arm, MT

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 Big Arm, MT

#1

T-Mobile

Coverage Score 80.0
In Big Arm, MT
Overall
87.7%
4G LTE
84.9% avg. -98 dBm 4G LTE signal where 4G LTE coverage exists: avg. -98 dBm
5G
85.6% avg. -94 dBm 5G signal where 5G coverage exists: avg. -94 dBm
Fast 5G
53.4% avg. -90 dBm Fast 5G signal where Fast 5G coverage exists: avg. -90 dBm
Lake County, MT covered 54.8%
#2

AT&T

Coverage Score 66.6
In Big Arm, MT
Overall
95.2%
4G LTE
95.2% avg. -110 dBm 4G LTE signal where 4G LTE coverage exists: avg. -110 dBm
5G
63.7% avg. -116 dBm 5G signal where 5G coverage exists: avg. -116 dBm
Fast 5G
59.6% avg. -116 dBm Fast 5G signal where Fast 5G coverage exists: avg. -116 dBm
Lake County, MT covered 62.8%
#3

Verizon

Coverage Score 48.3
In Big Arm, MT
Overall
99.3%
4G LTE
99.3% avg. -95 dBm 4G LTE signal where 4G LTE coverage exists: avg. -95 dBm
5G
3.4% avg. -108 dBm 5G signal where 5G coverage exists: avg. -108 dBm
Fast 5G
0.0%
Lake County, MT covered 55.4%

County coverage is shown for surrounding-area context and uses land-area only coverage.

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Best phone plans for Big Arm, MT

Best phone plans on T-Mobile's network for Big Arm, MT

80.0 T-Mobile coverage score Ranked #1 in Big Arm, MT
Best family plan
79.5 Value Score

T-Mobile Better Value

Fair Value

Price
$140.01/mo for 3 lines ($46.67/line)
Data
Unlimited
Hotspot
Unlimited
View plan
See all plans on T-Mobile Compare all phone plans

Coverage by ZIP code in Big Arm, MT

ZIP code areas can extend beyond city limits, so this table is best used for local comparison around the city.

ZIP Code AT&T T-Mobile Verizon
59860 90.2% 90.2% 66.1% 59.9% 76.1% 76.0% 68.2% 46.2% 84.1% 83.9% 43.3% 30.4%
59910 96.6% 96.6% 79.7% 74.8% 90.7% 90.7% 89.2% 77.3% 74.8% 74.8% 1.2% 0.0%

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 Big Arm, MT 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.