Traveling from Gregory to Rapid City covers 242.1 miles and typically takes about 4 hours and 29 minutes of drive time. Because this journey stays within the Great Plains region of South Dakota, you can comfortably complete the trip in a single day without needing an overnight stay. Expect to spend approximately $37 on fuel for the trek. You will primarily navigate via US Highway 18 and I-90, making this a straightforward route for those looking to reach the Black Hills area efficiently. It is a practical, no-nonsense drive that serves as a direct link between the rural landscape of Gregory and the more populated Rapid City.
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
1 planned break
Plan on a short reset every 3 to 4 hours to stay fresh behind the wheel.
Midpoint
121 miles from Gregory, SD
A natural place for your longest stop of the day
, about 2h 32m into the drive
.
Main Roads
Road
Distance
Duration
I 90
168.6 mi
2h 40m
307th Avenue
35.8 mi
51m
US Highway 18
34.4 mi
51m
I 190
1.4 mi
1m
Park Avenue
0.4 mi
<1m
East 6th Street
0.2 mi
1m
Mount Rushmore Road
0.2 mi
<1m
Omaha Street
0.2 mi
<1m
Longest stretch:
I 90
— 168.6 mi, about 2h 40m
Traffic on I-90
Hour-of-day weekday pattern from 24 FHWA count stations on your route.
Peak
4 PM
~765 veh/hr typical
· worst 1,010
Quietest
2 AM
~30 veh/hr
Peak-to-quiet ratio
25.5×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 51 weeks of 2023 FHWA Travel Monitoring Analysis System data. Weekday hours only (Mon–Fri).
Turn-by-Turn Driving Directions
Step-by-step road directions between Gregory, SD and Rapid City, SD.
1
Start on East 6th Street
0.2 mi·1 min·East 6th Street
2
At end of road, turn left onto SD 47
0.4 mi·43 sec·Park Avenue
3
Turn right onto US 18
34 mi·51 min·US Highway 18
4
Turn right onto US 183; SD 44; SD 53
36 mi·51 min·307th Avenue
5
Take the ramp
0.3 mi·44 sec
6
Merge onto I 90
169 mi·2 hr 40 min·I 90
7
Take the exit
0.4 mi·1 min
Toward I 190, US 16: Downtown, Black Hawk National Forest, Mount Rushmore
8
Continue on I 190
1.4 mi·1 min·I 190
9
Turn left onto US 16; SD 44
0.2 mi·39 sec·Omaha Street
Use the right lane.
10
Turn right onto US 16
0.2 mi·45 sec·Mount Rushmore Road
Use the right lane.
11
Arrive at destination
US 16
Trip Plan
Since the trip is just under four and a half hours, you have plenty of flexibility to depart whenever suits your schedule best. With only one recommended stop planned, try to time your break to coincide with your transition onto I-90 to maximize your momentum. Keep an eye on your fuel gauge during the initial segments on US Highway 18, as services may be more spread out before you hit the main interstate corridor. Because you are tackling a significant 168.6-mile stretch on the interstate, ensure your vehicle is prepped for sustained speeds to keep your total fuel costs near the estimated $37. Taking advantage of the single planned stop will help keep you refreshed as you navigate the transition from the Great Plains toward Rapid City.
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 121 miles from Gregory, SD, or about 2h 32m into the drive.
The longest continuous stretch on this route runs about 168.6 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 53 miles or 1h 18m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 121 miles or 2h 32m in
This is the best place for your longest stop, a real meal, and a full fuel check.
Final approach
Final hour starts around 3h 45m
Traffic, exits, and arrival timing usually matter more near Rapid City, SD than in the middle of the route.
Before You Leave
+
Open the route before leaving Gregory, 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 Gregory, SD
This is one driving day of about 242.1 miles and 4h 29m.
Your first comfortable stop window is around 53 miles from Gregory, 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 168.6 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Place data sourced from public business listings. Hours and availability may vary.
Heads-up: tricky spots
5 of 8
5 decision points cluster between mile 0.2 and 241.8 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
5
0.2 mi into trip|~1m in|SD 47 / Park Avenue
At end of road, turn left onto SD 47 / Park Avenue
Navigation decision point
4
0.6 mi into trip|~1m in|US 18 / US Highway 18
Turn right onto US 18 / US Highway 18
Navigation decision point
4
35 mi into trip|~52m in|US 183; SD 44; SD 53 / 307th Avenue
Turn right onto US 183; SD 44; SD 53 / 307th Avenue
Navigation decision point
5
239.8 mi into trip|~4h 25m in
Take the exit toward I 190, US 16: Downtown, Black Hawk National Forest, Mount Rushmore
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Toward I 190, US 16: Downtown, Black Hawk Natio...
7
241.8 mi into trip|~4h 28m in|US 16 / Mount Rushmore Road
Turn right onto US 16 / Mount Rushmore Road
Lane positioning matters here
Use the right lane.
Fuel & Cost
Regular Gas
$35.75 one way
$71.51 round trip
$3.75/gal25.4 MPG avg85 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.14
$39.47
$78.94
premium
$4.72
$44.95
$89.90
diesel
$4.80
$45.71
$91.43
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$36
Meals
$25–$50
Total
$61–$86
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 84.7 kg one way.
Prices: EIA weekly data, 2026-07-13.
Driving Electric?
About $25 in charging
· 0 stops
· 67% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
72.6
0
$25.42
$11.62
Efficient EV
60.5
0
$21.18
$9.68
EV Truck/SUV
96.8
1
$33.89
$15.49
Gas CO2
85 kg
EV CO2
28 kg (67% less)
Plan for 0 charging stops, roughly every 270 miles. Allow 25-40 minutes per stop at a DC fast charger.
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.
Forecast as of Jul 18, 2026
Origin
Gregory, SD
Late night
in Gregory on Sunday
Local time
5:28 AM
CDT
Current temp
92°F
Sunny
ENE 10 to 15 mph8% chanceLive forecast
Heat Advisory
Heat Advisory issued July 18 at 1:23AM MDT until July 19 at 9:00PM MDT by NWS Rapid City SD
Destination
Rapid City, SD
Late night
in Rapid City on Sunday
Local time
4:28 AM
MDT
Current temp
95°F
Mostly Sunny then Slight Chance Showers And Thunderstorms
SE 0 to 12 mph15% chanceLive forecast
Heat Advisory
Heat Advisory issued July 18 at 1:23AM MDT until July 19 at 9:00PM MDT by NWS Rapid City SD
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
3 degrees warmer at arrival
A meaningful temperature swing is a good cue to rethink layers, water, and how soon you want to arrive.
Road read
4h 29m on the road
An early start around 7-8 AM gets you there with plenty of daylight left.
Weather data from the National Weather Service. Conditions may change; check closer to your travel date.
National Parks Near This Route
Worth a detour if your schedule allows.
Mount Rushmore National Memorial
National Memorial
Majestic figures of George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln, surrounded by the beauty of the Black Hills of South Dakota, tell the story of the birth, growth, devel...
18 mi from route
~44 min detour
Free
near mile 242.1
The rugged beauty of the Badlands draws visitors from around the world. These striking geologic deposits contain one of the world’s richest fossil beds. Ancient horses and rhinos once roamed here. The...
25 mi from route
~62 min detour
$30
near mile 183.6
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This trip is heavily highway-focused, with 84% of your travel occurring on major thoroughfares. You will start on local roads before transitioning to US Highway 18 and eventually merging onto I-90. The backbone of your journey is a 168.6-mile stretch on I-90, which provides a consistent, high-speed experience across the plains. While the initial segments through 307th Avenue offer a more localized feel, the majority of your time behind the wheel will be spent maintaining steady interstate speeds. Anticipate a drive that prioritizes efficiency and connectivity over winding backroads or technical terrain.
84% highway — fuel and pacing are the main things to plan.
11 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 168.6 mi on I 90.
How Hard Is This Drive?
3/10
This is a straightforward highway drive that stays mostly on I 90 and 307th Avenue. There are only a few real navigation decisions along the way. The trickiest moment comes around 0.2 miles in near SD 47 / Park Avenue.
Driving Effort3/10
Easy - simple navigation with a manageable amount of wheel time
Balances navigation complexity with total wheel time.
This is a straightforward 4h 29m drive. You will face about 8 decision points, but nothing that requires special attention if you follow navigation.
Where does it get tricky?
The main spots that need attention: at 0.2 miles (SD 47 / Park Avenue): Navigation decision point; at 0.6 miles (US 18 / US Highway 18): Navigation decision point; at 35 miles (US 183; SD 44; SD 53 / 307th Avenue): Navigation decision point.
Rapid City is the largest city in the Badlands and Black Hills region of South Dakota. It is a convenient base for travel on to the Mount Rushmore National Memorial, the Crazy Horse Memorial, the Badlands, and the Black Hills National Forest.
Top landmarks
•Hotel Alex Johnson — building in Rapid City, South Dakota
•Dinosaur Park — sculpture park in Rapid City, South Dakota
The longest stretch is about 168.6 miles on I 90. The full list of main roads is in the Roads section above.
Yes — we found about 19 rest areas or service plazas within a short detour of the route (from OpenStreetMap). See the Rest Stops tab under Nearby Places for locations and mile markers. Plan to stretch, use the bathroom, and top off fluids every 2–3 hours on longer drives.
Yes, with realistic expectations. Build in a stop roughly every 2 hours, have snacks and activities ready, and check the Nearby Places tabs for kid-friendly stops along the way.
Mostly yes along the main roads, but rural stretches through SD can have sparse or no coverage. Before you leave, download offline Google Maps or Apple Maps for the route, and consider downloading music or podcasts instead of streaming. If you depend on data for navigation, keep a paper backup of the turn-by-turn directions.
The main spots that need attention: at 0.2 miles (SD 47 / Park Avenue): Navigation decision point; at 0.6 miles (US 18 / US Highway 18): Navigation decision point; at 35 miles (US 183; SD 44; SD 53 / 307th Avenue): Navigation decision point.
Yes — Mount Rushmore National Memorial and Badlands National Park. See the National Parks section for detour distances and tips on detours.
Possible but tiring. At 4.5 hours each way, an in-and-out day trip would put you behind the wheel for 9.0 hours — manageable with a long break at Rapid City, SD, but most travelers stay overnight.
