Distance between cities › USA › South Dakota › Armour, SD › Distance from Armour to Fallon Book Hotels

Distance from Armour, SD to Fallon, MT

Distance

554 mi

Time

10 hours 8 mins

Gas Cost

$52 - $100

There are 409.96 miles from Armour to Fallon in northwest direction and 554 miles (891.58 kilometers) by car, following the I-90 route.

Armour and Fallon are 10 hours 8 mins far apart, if you drive non-stop .

This is the fastest route from Armour, SD to Fallon, MT.

Please note the time difference between Armour, SD and Fallon, MT is 1 hour. The current time in Armour is 7:24 am and the current time in Fallon is 6:24 am.

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Lowest Price Rental Cars in Armour, SD

Planning on renting a car to go from Armour, SD to Fallon, MT? Here there are some offers to rent a car in Armour, SD

Small

From $14

Intermediate

From $18

Full-size

From $24

SUVs

From $28

Vans

From $40

Compare rental car prices in Armour »

Gas Consumption and Emissions

A car with a fuel efficiency of MPG will need 22.26 gallons of gas to cover the route between Armour, SD and Fallon, MT.

The estimated cost of gas to go from Armour to Fallon is $72.61.

During the route, an average car will release 436.13 pounds of CO₂ to the atmosphere. The carbon footprint would be 0.79 pounds of CO₂ per mile.

Average USA gas price used for calculation is $3.26 per gallon of regular gas. Price last updated on March 12, 2026.
Read more about our CO₂ calculation.

Halfway Point Between Armour, SD and Fallon, MT

If you want to meet halfway between Armour, SD and Fallon, MT or just make a stop in the middle of your trip, the exact coordinates of the halfway point of this route are 44.116989 and -102.932501, or 44º 7' 1.1604" N, 102º 55' 57.0036" W. This location is 277.14 miles away from Armour, SD and Fallon, MT and it would take approximately 5 hours 4 mins to reach the halfway point from both locations.

Closest City or Town to Halfway Point

The closest town to the halfway point is New Underwood, SD, situated 262 miles from Armour, SD and 294 miles from Fallon, MT. It would take 4 hours 21 mins to go from Armour to New Underwood and 5 hours 53 mins to go from Fallon to New Underwood.