Hill City, SD to Watertown, SD is 432.2 miles and takes about 7h 29m via I 90 and SD Highway 25, with a fuel budget near $69 and enough daylight to finish in a day. This drive stays within the Great Plains region, offering a consistent landscape for most of your trip. You'll primarily be on interstate highways, making it a straightforward transit. It's a solid choice if you're looking for an efficient way to cover ground across South Dakota without needing an overnight stay.
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
216.1 miles from Hill City, SD
A natural place for your longest stop of the day
, about 3h 36m into the drive
.
Main Roads
Road
Distance
Duration
I 90
287.7 mi
4h 30m
SD Highway 25
83.8 mi
1h 38m
South Highway 16
17.7 mi
21m
US Highway 212
14.5 mi
18m
9th Avenue Southwest
6.4 mi
8m
SD Highway 34
6 mi
7m
Elk Vale Road
5.3 mi
7m
Catron Boulevard
3.3 mi
4m
Longest stretch:
I 90
— 287.7 mi, about 4h 30m
Traffic on I-90
Hour-of-day weekday pattern from 23 FHWA count stations on your route.
Peak
2 PM
~319 veh/hr typical
· worst 563
Quietest
2 AM
~22 veh/hr
Peak-to-quiet ratio
14.5×
busier at peak than in the quiet hours
12a6anoon6p11p
Averaged across 52 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 Hill City, SD and Watertown, SD.
1
Start on Elm Street
62 ft·5 sec·Elm Street
2
Turn right onto US 16; US 385
0.7 mi·1 min·Main Street
3
Continue on US 16; US 385
3.0 mi·4 min·Highway 385
4
Continue on US 16; US 385
18 mi·21 min·South Highway 16
5
Continue on US 16
1.0 mi·1 min·Mount Rushmore Road
6
Take the exit onto US 16 Truck
0.1 mi·12 sec·US 16 Truck
7
Merge onto US 16 Truck
3.3 mi·4 min·Catron Boulevard
8
Continue on US 16 Truck
5.3 mi·7 min·Elk Vale Road
9
Take the exit
0.5 mi·1 min
10
Merge onto I 90; US 14
288 mi·4 hr 30 min·I 90; US 14
11
Take the exit
0.3 mi·47 sec
Toward SD 25: Emery, Farmer
12
Turn left onto SD 25
24 mi·27 min·SD Highway 25
13
Turn right onto SD 25; SD 34
6.0 mi·7 min·SD Highway 34
14
Turn left onto SD 25
60 mi·1 hr 10 min·SD Highway 25
15
At end of road, turn right onto US 212; SD 25
3.9 mi·5 min·US Highway 212
16
Continue on US 212
1.0 mi·1 min·4th Street
17
Continue on US 212
11 mi·12 min·US Highway 212
18
Continue on US 212
6.4 mi·8 min·9th Avenue Southwest
19
Turn left onto South Broadway
0.7 mi·1 min·South Broadway
20
Arrive at destination
South Broadway
Trip Plan
To make the most of this 7.5-hour drive, consider an early morning departure from Hill City to maximize daylight. With 2 recommended stops, you can break up the 432.2 miles into manageable segments. The longest stretch of highway is 287.7 miles on I 90, so plan your fuel and rest stops accordingly before you hit that part of the route. Keep an eye on your fuel gauge, especially as you transition to SD Highway 25, where services might be less frequent than on the interstate.
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 216.1 miles from Hill City, SD, or about 3h 36m into the drive.
The longest continuous stretch on this route runs about 287.7 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 95 miles or 1h 42m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 216.1 miles or 3h 36m 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 15m
Traffic, exits, and arrival timing usually matter more near Watertown, SD than in the middle of the route.
Before You Leave
+
Open the route before leaving Hill City, 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 Hill City, SD
This is one driving day of about 432.2 miles and 7h 29m.
Your first comfortable stop window is around 95 miles from Hill City, 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 287.7 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 11
5 decision points cluster between mile 0 and 409.6 — GPS handles the exact turns, but know they're coming. Your lane choice matters more than the turn itself.
4
0 mi into trip|~0m in|US 16; US 385 / Main Street
Turn right onto US 16; US 385 / Main Street
Navigation decision point
5
319.4 mi into trip|~5h 13m in
Take the exit toward SD 25: Emery, Farmer
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Toward SD 25: Emery, Farmer
4
319.8 mi into trip|~5h 14m in|SD 25 / SD Highway 25
Turn left onto SD 25 / SD Highway 25
Navigation decision point
4
343.6 mi into trip|~5h 41m in|SD 25; SD 34 / SD Highway 34
Turn right onto SD 25; SD 34 / SD Highway 34
Navigation decision point
5
409.6 mi into trip|~6h 59m in|US 212; SD 25 / US Highway 212
At end of road, turn right onto US 212; SD 25 / US Highway 212
Navigation decision point
Fuel & Cost
Regular Gas
$63.83 one way
$127.65 round trip
$3.75/gal25.4 MPG avg151 kg CO2
Fuel Type
$/gal
One Way
Round Trip
midgrade
$4.14
$70.46
$140.92
premium
$4.72
$80.25
$160.49
diesel
$4.80
$81.61
$163.22
No toll roads detected on this route.
Estimated Trip Cost (one way, 1 person)
Fuel
$64
Meals
$25–$50
Total
$89–$114
Rough estimate based on US averages. Hotel $80–$140/night, meals $25–$50/day.
Estimated CO2 emission: 151.2 kg one way.
Prices: EIA weekly data, 2026-07-13.
Driving Electric?
About $45 in charging
· 1 stop
· 66% less CO2
Vehicle Type
kWh
Stops
DC Fast
Home Charge
Average EV
129.7
1
$45.38
$20.75
Efficient EV
108.1
1
$37.82
$17.29
EV Truck/SUV
172.9
2
$60.51
$27.66
Gas CO2
151 kg
EV CO2
51 kg (66% 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.
Forecast as of Jul 17, 2026
Origin
Hill City, SD
Evening
in Hill City on Saturday
Local time
7:14 PM
MDT
Current temp
64°F
Mostly Clear
NW 1 mph6% chanceLive forecast
Heat Advisory
Heat Advisory issued July 16 at 7:09PM MDT until July 19 at 9:00PM MDT by NWS Rapid City SD
Heat Advisory
Heat Advisory issued July 16 at 11:50AM CDT until July 16 at 10:00PM CDT by NWS Aberdeen SD
Destination
Watertown, SD
Evening
in Watertown on Saturday
Local time
8:14 PM
CDT
Current temp
72°F
Clear
SSE 10 to 14 mph0% chanceLive forecast
Heat Advisory
Heat Advisory issued July 16 at 7:09PM MDT until July 19 at 9:00PM MDT by NWS Rapid City SD
Heat Advisory
Heat Advisory issued July 16 at 11:50AM CDT until July 16 at 10:00PM CDT by NWS Aberdeen 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 later
The destination clock does not match departure time, so double-check hotel check-in windows and late arrival plans.
Temperature spread
8 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
7h 29m 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.
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...
Immerse yourself in one of the longest caves in the world. With over 220 miles of mapped and surveyed passages, this underground wilderness appeals to human curiosity. Its splendor is revealed through...
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 89.4
Wind Cave National Park protects two very different worlds - one deep within the earth, the other a sunlit world of many resources. Bison, elk, and other wildlife roam the rolling prairie grasslands a...
Park data from the National Park Service API. Alerts update every 2 hours.
More Details
What kind of drive is this?
This route is 96% highway, so expect long stretches of driving on interstates and major highways. The longest continuous segment is 287.7 miles on I 90. You'll transition to surface roads, specifically SD Highway 25, for the final portion of the drive. The density of exits on I 90 means frequent opportunities for services before you reach the more rural cruising on state highways.
96% highway — fuel and pacing are the main things to plan.
20 navigation steps total — most of the decisions cluster near the start and finish.
Longest single stretch: 287.7 mi on I 90.
How Hard Is This Drive?
4/10
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 early in the drive near US 16; US 385 / Main Street.
Driving Effort4/10
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 29m, endurance matters. Plan breaks every 2-3 hours. The 11 decision points are all manageable with basic attention.
Where does it get tricky?
The main spots that need attention: near the start (US 16; US 385 / Main Street): Navigation decision point; at 319.4 miles: Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one; at 319.8 miles (SD 25 / SD Highway 25): Navigation decision point.
Elevation Profile
Hilly terrain with moderate elevation changes
4,985 ft1,320 ft
Total Climb
479 ft
Total Descent
3,727 ft
Highest Point
4,985 ft
Elevation Range
3,666 ft
Towns Mentioned on Route Signs
Based on OSRM destination-sign hints, not a full list of every settlement the road passes.
On the drive from Hill City, SD to Watertown, SD, road signs begin pointing toward Farmer along the way.
Hill City, in the Black Hills of western South Dakota, is known as the "Heart of the Hills", as it is close to the geographical center of the Black Hills.
The longest stretch is about 287.7 miles on I 90. The full list of main roads is in the Roads section above.
Yes — we found about 20 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.
It helps. This is a long drive, so arriving tired and in the dark compounds. If the last hour of the trip is on surface roads or mountain grades, aim to arrive at Watertown, SD before sunset when you can. Check the Trip Plan for departure windows that land you in daylight.
Only with planning. This is a long drive for kids — consider splitting it into two days rather than pushing through. Plan at least 2 meaningful breaks. There are 20 rest areas along the route for bathroom stops.
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: near the start (US 16; US 385 / Main Street): Navigation decision point; at 319.4 miles: Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one; at 319.8 miles (SD 25 / SD Highway 25): Navigation decision point.
Yes — Mount Rushmore National Memorial, Jewel Cave National Monument and Badlands National Park (4 total within detour distance). See the National Parks section for detour distances and tips on detours.
Not recommended in a single day. At 7.5 hours each way, a round trip means 15.0 hours of driving — that is an unsafe level of fatigue for most drivers. Plan at least one night at Watertown, SD before the return drive.
