Distance between cities › USA › South Dakota › Custer, SD › Distance from Custer to Boulder Book Hotels

Distance from Custer, SD to Boulder, WY

Distance

479 mi

Time

9 hours 10 mins

Gas Cost

$44 - $85

There are 315.95 miles from Custer to Boulder in southwest direction and 479 miles (770.88 kilometers) by car, following the US-20 and US-26 route.

Custer and Boulder are 9 hours 10 mins far apart, if you drive non-stop .

This is the fastest route from Custer, SD to Boulder, WY.

Custer, SD and Boulder, WY are in the same time zone (MDT). Current time in both locations is 11:45 pm.

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Lowest Price Rental Cars in Custer, SD

Planning on renting a car to go from Custer, SD to Boulder, WY? Here there are some offers to rent a car in Custer, SD

Small

From $14

Intermediate

From $18

Full-size

From $24

SUVs

From $28

Vans

From $40

Compare rental car prices in Custer »

Gas Consumption and Emissions

A car with a fuel efficiency of MPG will need 19.22 gallons of gas to cover the route between Custer, SD and Boulder, WY.

The estimated cost of gas to go from Custer to Boulder is $61.59.

During the route, an average car will release 376.59 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 $3.20 per gallon of regular gas. Price last updated on March 11, 2026.
Read more about our CO₂ calculation.

Halfway Point Between Custer, SD and Boulder, WY

If you want to meet halfway between Custer, SD and Boulder, WY or just make a stop in the middle of your trip, the exact coordinates of the halfway point of this route are 43.025972 and -106.762525, or 43º 1' 33.4992" N, 106º 45' 45.09" W. This location is 239.31 miles away from Custer, SD and Boulder, WY and it would take approximately 4 hours 35 mins to reach the halfway point from both locations.

Closest City or Town to Halfway Point

The closest town to the halfway point is Powder River, WY, situated 249 miles from Custer, SD and 229 miles from Boulder, WY. It would take 4 hours 51 mins to go from Custer to Powder River and 4 hours 19 mins to go from Boulder to Powder River.