How far is Spearfish, SD from Watertown, SD?
Fastest route
The distance between Spearfish, SD and Watertown, SD is 332.33 miles (534.62 kilometers) by car, following the I-90 and US-14 E route. The drive time is approximately 6 hours and 18 minutes. The halfway point is Reliance, SD.
Here are some recommended routes from Spearfish to Watertown by car:
- Route 1: 6 hours and 18 minutes, 332.33 miles
- US-14 W
- I-90 W
- US-14 W
- Route 2: 6 hours and 23 minutes, 336.8 miles
- US-14 W
- I-90 W
- US-212 W
- SD-14 S
- Route 3: 6 hours and 37 minutes, 373.8 miles
- US-14 W
- I-90 W
- US-14 W
- SD-34 W
Reverse, save, or send this route
This drive is better planned with a longer stop or an overnight stay. Copy the route link, send it to another device, or print a clean version before you head out.
This drive is better planned with a longer stop or an overnight stay.
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 06h 36m.
Starting early still helps, but most travelers will want a longer stop or an overnight stay on a route this long.
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.
City in and county seat of Lyman County, South Dakota, United States
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 Spearfish and Watertown.
Turn-by-Turn Driving Directions
Step-by-step road directions between Spearfish and Watertown.
-
1
Start on North Main Street
26 m · 30 sec · North Main Street
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2
Continue on North Main Street
51 m · 10 sec · North Main Street
-
3
Turn right onto East Jackson Boulevard
2777 ft · 2 min · East Jackson Boulevard
-
4
Take the ramp right toward I 90 East, US 85 South
1555 ft · 38 sec
-
5
Merge slight left
14.2 mi · 14 min
-
6
Continue straight
7.6 mi · 8 min
-
7
Continue straight
23.6 mi · 24 min
-
8
Continue straight
292.1 mi · 4 hr 36 min
-
9
Take the exit slight right toward SD 25: Emery, Farmer
1688 ft · 48 sec
-
10
Turn left onto SD Highway 25
23.8 mi · 28 min · SD Highway 25
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11
Turn right onto SD Highway 34
6 mi · 7 min · SD Highway 34
-
12
Turn left onto SD Highway 25
60 mi · 1 hr 11 min · SD Highway 25
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13
At the end of the road, turn right onto US Highway 212
3.9 mi · 6 min · US Highway 212
-
14
Continue on 4th Street
1 mi · 2 min · 4th Street
-
15
Continue on US Highway 212
10.6 mi · 12 min · US Highway 212
-
16
Continue on 9th Avenue Southwest
6.4 mi · 9 min · 9th Avenue Southwest
-
17
Turn left onto South Broadway
1.1 km · 2 min · South Broadway
-
18
Arrive at your destination
0 m · 1 sec · South Broadway
Car Route Details
A richer read on the saved driving route between Spearfish and Watertown.
Long-distance drive
This route is long enough that fuel, rest stops, weather, and timing matter more than any single maneuver.
I 90 East
Continue straight
292 mi · 04h 36m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
Better with a longer stop
This route is long enough that most travelers will be better off planning an overnight stay or a more deliberate stop window.
Sunny leaving Spearfish and Sunny near Watertown.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Spearfish to Watertown?
The road trip is about 384 miles (618 km) and usually takes 06h 36m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route is long enough that most travelers will be better off planning an overnight stay or a more deliberate stop window.
What is the halfway point on this route?
Kennebec is a useful midpoint, sitting about 225.2 miles from Spearfish and 158.8 miles from Watertown.
How much longer is the road route than the straight-line distance?
The direct path is about 332.4 miles (534.9 km), while the road route adds roughly 51.6 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 6:00 AM to 7:30 AM MDT. Starting early still helps, but most travelers will want a longer stop or an overnight stay on a route this long.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $51.10 one way or $102.19 round trip. Estimated CO2 is about 120.4 kg one way.
Do you cross a time zone on this route?
Yes. There is about a 1 hour time difference between Spearfish and Watertown, so arrival and return times should be read in local time.
What should you check before leaving?
Before you leave, expect Sunny around Spearfish and Sunny near Watertown.
Flight Path Map
This map shows the direct air route between Spearfish and Watertown. Straight-line distance: 332.35 mi (534.87 km).
#1 Spearfish
City in Lawrence County, South Dakota, United States
| Population | 11,900 |
| Coordinates | 44.4908200, -103.8593700 |
| Altitude | 1112 |
| Country | United States |
#2 Watertown
City in and county seat of Codington County, South Dakota, United States
| Population | 22,303 |
| Coordinates | 44.8994100, -97.1150700 |
| Altitude | 528 |
| Country | United States |
End: South Broadway (-97.115008, 44.899398)
Estimated Travel Time
Distance: 618 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 12h 47m |
| 40 mph (64.37 km/h) | 09h 36m |
| 50 mph (80.47 km/h) | 07h 40m |
| 60 mph (96.56 km/h) | 06h 23m |
| 70 mph (112.65 km/h) | 05h 29m |
| 80 mph (129 km/h) | 04h 47m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.77 | $51.10 | $102.19 |
| Mid-grade | $4.25 | $57.63 | $115.26 |
| Premium | $4.65 | $63.06 | $126.12 |
| Diesel | $5.30 | $71.87 | $143.74 |
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 · May 02, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.