How far is Keystone, SD from New Underwood, SD?
The driving distance from Keystone, SD to New Underwood, SD is about 42.6 miles (68.5 km), with a travel time of about 00h 45m by car.
- The straight-line flight distance is about 32 miles (51.5 km).
- For a round trip, plan for roughly 01h 30m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 7:00 AM to 7:00 PM MDT.
Reverse, save, or send this route
This is an easy same-day return drive. Copy the route link, send it to another device, or print a clean version before you head out.
This is an easy same-day return drive.
Flight Distance
Driving Distance
Gas Cost Calculator
Leave and Arrive Planner
Pick a departure time to see your estimated arrival and same-day return window.
Drive time stays fixed at 00h 45m.
This is a short drive, so your comfort window is wide. Traffic and current weather matter more than the clock.
You are leaving earlier than the recommended window, which gives you extra margin for breaks and traffic.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
Census-designated place in Pennington County, South Dakota
Route Weather Snapshot
Check the forecast at both ends before you head out.
Sunny
Driving Route Map
The map below follows the saved road route between Keystone and New Underwood.
Turn-by-Turn Driving Directions
Step-by-step road directions between Keystone and New Underwood.
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1
Start on the route
28 m · 12 sec
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2
Turn left onto 1st Street
155 m · 17 sec · 1st Street
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3
Continue on Reed Street
1798 ft · 1 min · Reed Street
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4
Turn right onto Highway 16A
2.3 mi · 4 min · Highway 16A
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5
Keep slight right
1699 ft · 41 sec
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6
Merge slight left onto South Highway 16
12.1 mi · 14 min · South Highway 16
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7
Continue on Mount Rushmore Road
1 mi · 1 min · Mount Rushmore Road
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8
Take the exit slight right
577 ft · 12 sec
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9
Merge slight left onto Catron Boulevard
3.3 mi · 5 min · Catron Boulevard
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10
Continue on Elk Vale Road
5.3 mi · 7 min · Elk Vale Road
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11
Take the exit slight right
2710 ft · 1 min
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12
Merge slight left
15.8 mi · 16 min
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13
Take the exit slight right toward New Underwood
1405 ft · 35 sec
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14
Turn right onto 161st Avenue
2371 ft · 1 min · 161st Avenue
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15
Turn right onto Highway 1416
1895 ft · 43 sec · Highway 1416
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16
Turn left onto South A Avenue
1084 ft · 30 sec · South A Avenue
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17
Arrive at your destination
0 m · 1 sec · South A Avenue
Car Route Details
A richer read on the saved driving route between Keystone and New Underwood.
Turn-heavy local drive
The route has frequent decision points for its length, so lane choice and turn timing will matter more than cruising speed.
Elk Vale Road
Merge slight left
15.8 mi · 00h 16m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A short regional drive
This route is short enough to handle as a quick errand, commute, or easy same-day return without much planning overhead.
Sunny leaving Keystone and Sunny near New Underwood.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Keystone to New Underwood?
The road trip is about 42.6 miles (68.5 km) and usually takes 00h 45m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route is short enough to handle as a quick errand, commute, or easy same-day return without much planning overhead.
What is the halfway point on this route?
Rapid Valley is a useful midpoint, sitting about 21.3 miles from Keystone and 21.3 miles from New Underwood.
How much longer is the road route than the straight-line distance?
The direct path is about 32 miles (51.5 km), while the road route adds roughly 10.6 extra miles because roads do not follow the straight air line.
When is the best time to leave for this route?
A good departure window is usually 7:00 AM to 7:00 PM MDT. If you want a more comfortable same-day return, try to leave by 7:00 PM MDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $5.66 one way or $11.31 round trip. Estimated CO2 is about 13.3 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Keystone and Sunny near New Underwood.
Stop Ideas Near Rapid Valley
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Willow Park
Box Elder City Hall
Box Elder Water Department
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Rapid Valley.
Flight Path Map
This map shows the direct air route between Keystone and New Underwood. Straight-line distance: 31.99 mi (51.49 km).
#1 Keystone
Town in Pennington County, South Dakota
| Population | 352 |
| Coordinates | 43.8955400, -103.4182500 |
| Altitude | 1320 |
| Country | United States |
#2 New Underwood
Human settlement in Pennington County, South Dakota, United States of America
| Population | 679 |
| Coordinates | 44.0933200, -102.8362800 |
| Altitude | 867 |
| Country | United States |
End: South A Avenue (-102.836368, 44.09332)
Estimated Travel Time
Distance: 68 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 01h 25m |
| 40 mph (64.37 km/h) | 01h 03m |
| 50 mph (80.47 km/h) | 00h 51m |
| 60 mph (96.56 km/h) | 00h 42m |
| 70 mph (112.65 km/h) | 00h 36m |
| 80 mph (129 km/h) | 00h 31m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $5.66 | $11.31 |
| Mid-grade | $4.25 | $6.38 | $12.76 |
| Premium | $4.65 | $6.98 | $13.96 |
| Diesel | $5.30 | $7.96 | $15.91 |
Assumes 8.3 L/100 km (about 28.3 MPG). CO2 is an estimate and varies by vehicle, fuel blend, traffic, and terrain.
Prices in South Dakota · Apr 19, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.