Origin
Spearfish, SD
Morning in Spearfish on Thursday
Local time
10:59 AM
MDT
Current temp
73°F
Unavailable
Live forecast
Trip from Spearfish, SD to Porcupine, SD
Last recalculated Apr 16, 2026
Drive Time
3h 40m
Distance
131.6 mi
212 km
Drive Score
9/10
Great drive
Same Day?
Yes, doable
Fuel Cost
$21
one way
EV Charging
Unknown
Best Time to Leave
4 AM
3h 28m
★
6 AM
3h 41m
8 AM
4h 6m
10 AM
3h 49m
12 PM
3h 47m
3 PM
3h 51m
5 PM
4h 5m
8 PM
3h 33m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Spearfish, SD
Wikimedia Commons
Porcupine, SD
Magda Ehlers
Trip Overview
The drive from Spearfish, SD to Porcupine, SD covers 131.6 miles and takes about 3h 40m behind the wheel. This route is realistic as a one-day drive if you keep your stops efficient.
The route leans on I 90, East Highway 44, North Big Foot Trail for much of the mileage, and the overall profile is highway-focused drive. The longest uninterrupted segment is about 47.5 miles on I 90. At current regular gas prices, budget about $20.57 one way before food or hotel costs.
Trip Pace
Same-day drive is realistic
A same-day return is realistic if you keep stops short.
Break Rhythm
1 planned break
A short stop every 2 to 3 hours is enough for this drive.
Midpoint
65.8 miles from Spearfish, SD
A natural place for your longest stop of the day , about 1h 20m into the drive .
Who Is This Route For?
Weekend Trip
Doable as a same-day drive at 3h 40m. Total distance: 131.6 miles.
Family Friendly
Moderate complexity with 1 natural rest stops along the way.
Solo Traveler
3h 40m drive, comfortable solo distance.
First-Time Driver
Mostly highway driving (72%). Straightforward navigation.
Drive Character
This is a 3h 40m highway drive covering 131.6 miles, with most of the trip on I 90 and East Highway 44. The longest continuous stretch is about 47.5 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 21 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 47.5 miles.
How Hard Is This Drive?
This is a straightforward highway drive that stays mostly on I 90 and East Highway 44. There are only a few real navigation decisions along the way. The trickiest moment comes early in the drive near East Jackson Boulevard.
Driving Effort
3/10
Easy - simple navigation with a manageable amount of wheel time
Balances navigation complexity with total wheel time.
This is a straightforward 3h 40m drive. You will face about 11 decision points, but nothing that requires special attention if you follow navigation.
Where does it get tricky?
The main spots that need attention: near the start (East Jackson Boulevard): Navigation decision point; at 0.6 miles: Multiple destination signs - pick the right one; at 48.4 miles: Exit ramp - move to the correct lane early.
Critical Maneuvers
5 of 11 key pointsThese are the spots where you need to pay the most attention. Preview them before you drive.
4
0 mi into trip
|
~0m in
|
East Jackson Boulevard
Turn right onto East Jackson Boulevard
Navigation decision point
5
0.6 mi into trip
|
~2m in
Take the ramp toward I 90 East, US 85 South
Multiple destination signs - pick the right one
Toward I 90 East, US 85 South
4
48.4 mi into trip
|
~51m in
Take the exit toward East North Street
Exit ramp - move to the correct lane early
Toward East North Street
5
48.6 mi into trip
|
~51m in
Keep slight right at fork
Highway fork - watch signs carefully
4
131.6 mi into trip
|
~3h 40m in
|
Main Street
Turn left onto Main Street
Navigation decision point
Main Roads
| Road | Distance | Duration |
|---|---|---|
| I 90 | 47.5 mi | 48m |
| East Highway 44 | 40.3 mi | 1h 6m |
| North Big Foot Trail | 19.2 mi | 46m |
| Big Foot Trail | 7.9 mi | 19m |
| Bombing Range Road | 6.8 mi | 16m |
| Bureau of Indian Affairs Highway 27 | 6.8 mi | 16m |
| East North Street | 1 mi | 2m |
| East Jackson Boulevard | 0.5 mi | 1m |
Longest stretch:
I 90
— 47.5 mi, about 48m
Turn-by-Turn Driving Directions
Step-by-step road directions between Spearfish, SD and Porcupine, SD.
1
Start on I 90 Business
85 ft
·
30 sec
·
North Main Street
2
Continue on I 90 Business
166 ft
·
9 sec
·
North Main Street
3
Turn right onto East Jackson Boulevard
0.5 mi
·
1 min
·
East Jackson Boulevard
4
Take the ramp
0.3 mi
·
37 sec
Toward I 90 East, US 85 South
5
Merge onto I 90; US 14; US 85
14 mi
·
14 min
·
I 90; US 14; US 85
6
Continue on I 90; US 14; SD 34
7.6 mi
·
7 min
·
I 90; US 14; SD 34
7
Continue on I 90; US 14; SD 79
24 mi
·
24 min
·
I 90; US 14; SD 79
8
Continue on I 90; US 14; US 16 Truck; SD 79
2.1 mi
·
2 min
·
I 90; US 14; US 16 Truck; SD 79
9
Take the exit
0.3 mi
·
30 sec
Toward East North Street
10
Keep slight right at fork
0.1 mi
·
15 sec
11
Turn straight onto I 90 Business
1.0 mi
·
2 min
·
East North Street
Use the left lane.
12
Turn left onto North Cambell Street
0.4 mi
·
1 min
·
North Cambell Street
13
Turn left onto SD 44
40 mi
·
1 hr 6 min
·
East Highway 44
14
Turn right onto Main Street
0.4 mi
·
56 sec
·
Main Street
15
Continue on Bombing Range Road
6.8 mi
·
16 min
·
Bombing Range Road
16
Continue on BIA 27
7.9 mi
·
19 min
·
Big Foot Trail
17
Continue on BIA 27
6.8 mi
·
16 min
·
Bureau of Indian Affairs Highway 27
18
Continue on BIA 27
19 mi
·
46 min
·
North Big Foot Trail
19
Turn left onto Main Street
124 ft
·
8 sec
·
Main Street
20
Turn left onto Eagle Drive
29 ft
·
1 sec
·
Eagle Drive
21
Arrive at destination
Eagle Drive
Trip Plan
Morning Departure
An early start around 7-8 AM gets you there with plenty of daylight left.
Evening Departure
A late afternoon start means arriving after dark. Morning is better.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 65.8 miles from Spearfish, SD, or about 1h 20m into the drive.
The longest continuous stretch on this route runs about 47.5 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 29 miles or 31m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 65.8 miles or 1h 20m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 2h 43m
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 Spearfish, 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.
Day 1
Settle into the route from Spearfish, SD
This is one driving day of about 131.6 miles and 3h 40m.
Your first comfortable stop window is around 29 miles from Spearfish, SD.
This route can stay practical as a one-day drive if traffic stays reasonable.
Plan about 1 real break rather than only quick fuel stops.
The longest stretch is on I 90 for about 47.5 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Halfway Point
Midpoint
About 65.8 mi from Spearfish, SD · 1h 20m into the drive
Mid-route town
Meal stop
66 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 29 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 65.8 miles from Spearfish, SD, which is a good place for a longer meal and fuel stop.
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.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Fuel & Cost
Regular Gas
$20.57 one way
$41.15 round trip
$3.97/gal
25.4 MPG avg
46 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.36 | $22.59 | $45.18 |
| premium | $4.89 | $25.33 | $50.65 |
| diesel | $5.61 | $29.06 | $58.11 |
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$21
Meals
$25–$50
Total
$46–$71
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 46 kg one way. Prices: EIA weekly data, 2026-04-13.
Driving Electric?
About $14 in charging · 0 stops · 67% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 39.5 | 0 | $13.82 | $6.32 |
| Efficient EV | 32.9 | 0 | $11.51 | $5.26 |
| EV Truck/SUV | 52.6 | 0 | $18.42 | $8.42 |
Gas CO2
46 kg
EV CO2
15 kg (67% less)
This trip is well within single-charge range for most EVs. No charging stops needed if you start fully charged.
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
10:59 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
Same local time
Origin and destination are on the same clock, so arrival timing is easier to judge at a glance.
Temperature spread
47 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
3h 40m on the road
Use the two city cards together: check the sky where you start, then compare it with the local time and temperature at arrival.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
Frequently Asked Questions
The drive from Spearfish, SD to Porcupine, SD covers 131.6 miles and takes about 3h 40m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are I 90, East Highway 44, North Big Foot Trail. Most of the drive stays on highways, so watch for ramps and exits.
This is a comfortable same-day trip.
The midpoint is about 65.8 miles from Spearfish, SD. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $20.57 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
An early start around 7-8 AM gets you there with plenty of daylight left. A late afternoon start means arriving after dark. Morning is better.
Plan about 1 meaningful break for fuel, food, or rest. A short stop every 2 to 3 hours is enough for this drive.
This is a straightforward 3h 40m drive. You will face about 11 decision points, but nothing that requires special attention if you follow navigation.
The main spots that need attention: near the start (East Jackson Boulevard): Navigation decision point; at 0.6 miles: Multiple destination signs - pick the right one; at 48.4 miles: Exit ramp - move to the correct lane early.
The route from Spearfish, SD to Porcupine, SD does not surface many named destination signs beyond the main corridor.
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