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

Distance from Armour, SD to Acton, MT

Distance

613 mi

Time

10 hours 46 mins

Gas Cost

$57 - $111

There are 538.80 miles from Armour to Acton in northwest direction and 613 miles (986.53 kilometers) by car, following the I-90 route.

Armour and Acton are 10 hours 46 mins far apart, if you drive non-stop .

This is the fastest route from Armour, SD to Acton, MT. The halfway point is Spearfish Canyon, SD.

Please note the time difference between Armour, SD and Acton, MT is 1 hour. The current time in Armour is 5:52 am and the current time in Acton is 4:52 am.

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Lowest Price Rental Cars in Armour, SD

Planning on renting a car to go from Armour, SD to Acton, 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 24.60 gallons of gas to cover the route between Armour, SD and Acton, MT.

The estimated cost of gas to go from Armour to Acton is $80.25.

During the route, an average car will release 482 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 Acton, MT

If you want to meet halfway between Armour, SD and Acton, MT or just make a stop in the middle of your trip, the exact coordinates of the halfway point of this route are 44.477829 and -103.795395, or 44º 28' 40.1844" N, 103º 47' 43.422" W. This location is 306.29 miles away from Armour, SD and Acton, MT and it would take approximately 5 hours 23 mins to reach the halfway point from both locations.

Closest City or Town to Halfway Point

The closest town to the halfway point is Spearfish Canyon, SD, situated 328 miles from Armour, SD and 342 miles from Acton, MT. It would take 4 hours 31 mins to go from Armour to Spearfish Canyon and 5 hours 24 mins to go from Acton to Spearfish Canyon.