Origin
Watertown, SD
Afternoon in Watertown on Thursday
Local time
12:15 PM
CDT
Current temp
70°F
Unavailable
Live forecast
Trip from Watertown, SD to Porcupine, SD
Last recalculated Apr 16, 2026
Drive Time
7h 50m
Distance
420.6 mi
677 km
Drive Score
8/10
Great drive
Same Day?
Yes, doable
Fuel Cost
$66
one way
EV Charging
Unknown
Best Time to Leave
4 AM
7h 41m
★
6 AM
7h 50m
8 AM
8h 9m
10 AM
7h 57m
12 PM
7h 55m
3 PM
7h 58m
5 PM
8h 8m
8 PM
7h 45m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Watertown, SD
Wikimedia Commons
Porcupine, SD
Magda Ehlers
Trip Overview
The drive from Watertown, SD to Porcupine, SD covers 420.6 miles and takes about 7h 50m behind the wheel. This route is realistic as a one-day drive if you keep your stops efficient.
The route leans on I 90, SD Highway 25, US 18 for much of the mileage, and the overall profile is highway-focused drive. The longest uninterrupted segment is about 199.2 miles on I 90. At current regular gas prices, budget about $65.76 one way before food or hotel costs.
Trip Pace
Same-day drive is realistic
A same-day return is possible, but it will make for a full day on the road.
Break Rhythm
2 planned breaks
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
210.3 miles from Watertown, SD
A natural place for your longest stop of the day , about 3h 47m into the drive .
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 7h 50m. Total distance: 420.6 miles.
Family Friendly
Moderate complexity with 2 natural rest stops along the way.
Solo Traveler
7h 50m drive, plan rest stops for pacing.
First-Time Driver
Mostly highway driving (94%). Straightforward navigation.
Drive Character
This is a 7h 50m highway drive covering 420.6 miles, with most of the trip on I 90 and SD Highway 25. The longest continuous stretch is about 199.2 miles on I 90.
Most of the miles stay on highways, which makes pacing and fuel planning easier than turn-by-turn city driving.
There are about 18 navigation steps in the underlying route data, so the final approach matters more than the middle miles.
I 90 is the longest continuous segment at about 199.2 miles.
How Hard Is This Drive?
This is a straightforward highway drive that stays mostly on I 90 and SD Highway 25. There are only a few real navigation decisions along the way. The trickiest moment comes around 22.6 miles in near SD 25 / SD Highway 25.
Driving Effort
4/10
Easy - simple navigation with a manageable amount of wheel time
Balances navigation complexity with total wheel time.
The route itself is not hard, but at 7h 50m, endurance matters. Plan breaks every 2-3 hours. The 12 decision points are all manageable with basic attention.
Where does it get tricky?
The main spots that need attention: at 22.6 miles (SD 25 / SD Highway 25): Navigation decision point; at 88.7 miles (SD 25 / SD Highway 25): Navigation decision point; at 311.8 miles: Exit ramp - move to the correct lane early.
Critical Maneuvers
5 of 12 key pointsThese are the spots where you need to pay the most attention. Preview them before you drive.
4
22.6 mi into trip
|
~30m in
|
SD 25 / SD Highway 25
Turn left onto SD 25 / SD Highway 25
Navigation decision point
4
88.7 mi into trip
|
~1h 47m in
|
SD 25 / SD Highway 25
Turn left onto SD 25 / SD Highway 25
Navigation decision point
4
311.8 mi into trip
|
~5h 22m in
Take the exit toward SD 73 North: Kadoka
Exit ramp - move to the correct lane early
Toward SD 73 North: Kadoka
4
312.1 mi into trip
|
~5h 23m in
|
I 90 Business; SD 73 / SD Highway 73
Turn left onto I 90 Business; SD 73 / SD Highway 73
Navigation decision point
4
357.9 mi into trip
|
~6h 17m in
|
US 18; SD 73
Turn right onto US 18; SD 73
Navigation decision point
Main Roads
| Road | Distance | Duration |
|---|---|---|
| I 90 | 199.2 mi | 3h 6m |
| SD Highway 25 | 83.6 mi | 1h 38m |
| US 18 | 48.1 mi | 57m |
| State Highway 73 | 44.6 mi | 51m |
| Big Foot Trail | 14.6 mi | 35m |
| US Highway 212 | 14.5 mi | 18m |
| 9th Avenue Southwest | 6.4 mi | 8m |
| SD Highway 34 | 6 mi | 7m |
Longest stretch:
I 90
— 199.2 mi, about 3h 6m
Turn-by-Turn Driving Directions
Step-by-step road directions between Watertown, SD and Porcupine, SD.
1
Start on South Broadway
0.7 mi
·
1 min
·
South Broadway
2
Turn right onto US 212
6.4 mi
·
8 min
·
9th Avenue Southwest
3
Continue on US 212
11 mi
·
12 min
·
US Highway 212
4
Continue on US 212
1.0 mi
·
1 min
·
4th Street
5
Continue on US 212
3.9 mi
·
5 min
·
US Highway 212
6
Turn left onto SD 25
60 mi
·
1 hr 10 min
·
SD Highway 25
7
Turn right onto SD 25; SD 34
6.0 mi
·
7 min
·
SD Highway 34
8
Turn left onto SD 25
24 mi
·
27 min
·
SD Highway 25
9
Take the ramp
0.3 mi
·
43 sec
10
Merge onto I 90
199 mi
·
3 hr 6 min
·
I 90
11
Take the exit
0.3 mi
·
47 sec
Toward SD 73 North: Kadoka
12
Turn left onto I 90 Business; SD 73
1.2 mi
·
2 min
·
SD Highway 73
13
Continue on SD 73
45 mi
·
51 min
·
State Highway 73
14
Turn right onto US 18; SD 73
48 mi
·
57 min
·
US 18; SD 73
15
Turn right onto BIA 27
15 mi
·
35 min
·
Big Foot Trail
16
Turn right onto Main Street
124 ft
·
8 sec
·
Main Street
17
Turn left onto Eagle Drive
29 ft
·
1 sec
·
Eagle Drive
18
Arrive at destination
Eagle Drive
Trip Plan
Morning Departure
Start early — leave by 6-7 AM to arrive at a reasonable hour.
Evening Departure
This is a long drive — plan for a morning departure or consider splitting it into two days.
You can normally do this drive in one day.
Plan roughly 2 meaningful breaks for fuel, food, and rest.
The halfway point lands around 210.3 miles from Watertown, SD, or about 3h 47m into the drive.
The longest continuous stretch on this route runs about 199.2 miles.
This is a comfortable same-day trip.
Departure
Before you leave
Start with fuel, water, and navigation already sorted so the first hour feels easy.
First stop
Around 93 miles or 1h 52m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 210.3 miles or 3h 47m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 6h 20m
Traffic, exits, and arrival timing usually matter more near Porcupine, SD than in the middle of the route.
Before You Leave
+
Open the route before leaving Watertown, SD so your first major turns are already loaded.
+
Leave with enough water and a charging cable within reach, not packed away.
+
Check your fuel range against the first long segment, especially if you are starting outside city service areas.
+
Pick one backup stop option before the midpoint in case traffic changes your pacing.
Day 1
Settle into the route from Watertown, SD
This is one driving day of about 420.6 miles and 7h 50m.
Your first comfortable stop window is around 93 miles from Watertown, SD.
This route can stay practical as a one-day drive if traffic stays reasonable.
Plan about 2 real breaks rather than only quick fuel stops.
The longest stretch is on I 90 for about 199.2 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Halfway Point
Midpoint
About 210.3 mi from Watertown, SD · 3h 47m into the drive
Mid-route town
Meal stop
210 mi into the route
Best for: Lunch, fuel, and a longer reset
This sits close to the middle of the route, so it works well for the longest stop of the day.
Pacing Suggestions
Fuel and coffee
A short stop after about 93 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 210.3 miles from Watertown, SD, which is a good place for a longer meal and fuel stop.
Before the longest stretch
Fuel checkTop up before I 90 if your tank is already low. That segment runs about 199.2 miles.
Arriving in Porcupine, SD
The final approach into Porcupine, SD usually feels slower than the middle of the drive, so avoid planning your tightest schedule at the very end.
Try to arrive with enough fuel left to skip an immediate station stop unless you already know the area around Porcupine, SD.
After long uninterrupted mileage, take five minutes before the last urban segment to reset and refocus on exits, merges, and city traffic.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Fuel & Cost
Regular Gas
$65.76 one way
$131.51 round trip
$3.97/gal
25.4 MPG avg
147 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.36 | $72.20 | $144.39 |
| premium | $4.89 | $80.94 | $161.88 |
| diesel | $5.61 | $92.86 | $185.73 |
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$66
Meals
$25–$50
Total
$91–$116
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 147.2 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $44 in charging · 1 stop · 67% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 126.2 | 1 | $44.16 | $20.19 |
| Efficient EV | 105.2 | 1 | $36.80 | $16.82 |
| EV Truck/SUV | 168.2 | 2 | $58.88 | $26.92 |
Gas CO2
147 kg
EV CO2
49 kg (67% less)
Plan for 1 charging stop. A 30-minute DC fast charge mid-route should be enough to complete the trip comfortably.
DC fast charging avg $0.35/kWh. Home charging avg $0.16/kWh. US grid CO2: 0.39 kg/kWh.
Travel Intel
Current conditions at both ends of the drive.
Destination
Porcupine, SD
Morning in Porcupine on Thursday
Local time
11:15 AM
MDT
Current temp
26°F
Unavailable
Live forecast
Seasonal Notes
Summer travel usually means heavier construction, hotter rest stops, and busier weekend traffic around major cities.
Winter travel shortens daylight, so a route that looks manageable on paper can feel much longer after dark.
Holiday weekends tend to make both departure and arrival windows slower than the raw route time suggests.
Time zone
1 hour earlier
The destination clock does not match departure time, so double-check hotel check-in windows and late arrival plans.
Temperature spread
44 degrees cooler at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
7h 50m on the road
Start early — leave by 6-7 AM to arrive at a reasonable hour.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
Frequently Asked Questions
The drive from Watertown, SD to Porcupine, SD covers 420.6 miles and takes about 7h 50m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are I 90, SD Highway 25, US 18. Most of the drive stays on highways, so watch for ramps and exits.
This is a comfortable same-day trip.
The midpoint is about 210.3 miles from Watertown, SD. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $65.76 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
Start early — leave by 6-7 AM to arrive at a reasonable hour. This is a long drive — plan for a morning departure or consider splitting it into two days.
Plan about 2 meaningful breaks for fuel, food, or rest. Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
The route itself is not hard, but at 7h 50m, endurance matters. Plan breaks every 2-3 hours. The 12 decision points are all manageable with basic attention.
The main spots that need attention: at 22.6 miles (SD 25 / SD Highway 25): Navigation decision point; at 88.7 miles (SD 25 / SD Highway 25): Navigation decision point; at 311.8 miles: Exit ramp - move to the correct lane early.
The route from Watertown, SD to Porcupine, SD does not surface many named destination signs beyond the main corridor.
Was this helpful?
Thanks for your feedback!
Your tip has been submitted. Thanks!
/500
Recent Tips
·
Explore More
More trips to Porcupine, SD
Explore more options from Watertown, SD or browse trips ending in Porcupine, SD.
Looking for more statewide routes? Browse SD road trips.
Explore maps for Watertown, SD or Porcupine, SD on MapSof.net.