Origin
Thermopolis, WY
Afternoon in Thermopolis on Sunday
Local time
4:48 PM
MDT
Current temp
27°F
Unavailable
Live forecast
Trip from Thermopolis, WY to Casper, WY
Drive Time
2h 39m
Distance
133.8 mi
215 km
Drive Score
9/10
Great drive
Same Day?
Yes, doable
Fuel Cost
$21
one way
EV Charging
Loading...
station data
Best Time to Leave
4 AM
2h 29m
★
6 AM
2h 40m
8 AM
3h 1m
10 AM
2h 47m
12 PM
2h 45m
3 PM
2h 48m
5 PM
3h 0m
8 PM
2h 33m
Estimated drive times based on typical traffic patterns. Actual times may vary with weather, construction, and real-time conditions.
Casper, WY
Beyzaa Yurtkuran
Trip Overview
Spanning 133.8 miles across the heart of the Mountain West, the drive from Thermopolis to Casper is a straightforward journey that typically takes about 2 hours and 39 minutes. Because the trip is relatively short, it functions perfectly as a single-day excursion, allowing you to reach your destination without needing an overnight stop. You should budget approximately $21 for fuel to complete the trek. The route primarily utilizes West US Highway 20-26, US 20, and East 2nd Street to navigate between these two Wyoming hubs. Whether you are traveling for business or leisure, this path offers a reliable connection through the region's rugged landscape.
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
66.9 miles from Thermopolis, WY
A natural place for your longest stop of the day , about 1h 19m into the drive .
Drive Character
This highway-focused drive is defined by a consistent pace, with 71% of the journey spent on major thoroughfares. You will encounter a longest uninterrupted stretch of 60.7 miles on West US Highway 20-26, which allows for steady progress through the terrain. The road personality shifts from open highway cruising to local navigation as you approach the city limits of Casper. Expect a functional, direct experience behind the wheel that prioritizes efficiency over technical, winding backroads. It is a classic Wyoming drive where the open road dictates the rhythm of your travel.
Most of the miles stay on highways, which makes pacing and fuel planning easier than turn-by-turn city driving.
There are about 11 navigation steps in the underlying route data, so the final approach matters more than the middle miles.
West US Highway 20-26 is the longest continuous segment at about 60.7 miles.
How Hard Is This Drive?
This is a straightforward highway drive that stays mostly on West US Highway 20-26 and US 20. There are only a few real navigation decisions along the way. The trickiest moment comes early in the drive near US 20; WY 789 / South 6th Street.
Route Complexity
3/10
Easy - simple navigation with a manageable amount of wheel time
This is a straightforward 2h 39m 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: near the start (US 20; WY 789 / South 6th Street): Lane positioning matters here; at 0.5 miles (US 20; WY 789 / Shoshoni Street): Lane positioning matters here; at 128.9 miles: Exit ramp - move to the correct lane early.
Critical Maneuvers
5 of 8 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
|
US 20; WY 789 / South 6th Street
Depart onto US 20; WY 789 / South 6th Street
Lane positioning matters here
Use the straight / left / right lanes.
4
0.5 mi into trip
|
~1m in
|
US 20; WY 789 / Shoshoni Street
Turn right onto US 20; WY 789 / Shoshoni Street
Lane positioning matters here
Use the left / slight right lanes.
4
128.9 mi into trip
|
~2h 29m in
Take the exit
Exit ramp - move to the correct lane early
5
131.4 mi into trip
|
~2h 33m in
|
US 20; US 26; US 87
Take the exit onto US 20; US 26; US 87 toward US 20 East, US 26 East, US 87 South: North Beverly Street, Bryan Stock Trail
Exit ramp - move to the correct lane early. Multiple destination signs - pick the right one
Toward US 20 East, US 26 East, US 87 South: Nor...
4
131.7 mi into trip
|
~2h 33m in
|
I 25 Business / Bryan Stock Trail
At end of road, turn left onto I 25 Business / Bryan Stock Trail
Navigation decision point
Main Roads
| Road | Distance | Duration |
|---|---|---|
| West US Highway 20-26 | 60.7 mi | 1h 8m |
| US 20 | 34 mi | 40m |
| East 2nd Street | 33.1 mi | 37m |
| Bryan Stock Trail | 1.1 mi | 2m |
| East Sunlight Drive | 0.9 mi | 3m |
| Shoshoni Street | 0.9 mi | 2m |
| South 6th Street | 0.5 mi | 1m |
| North Sunlight Drive | Unavailable | Refreshing |
Per-road distance and duration are being refreshed from OSRM for this route.
Longest stretch:
West US Highway 20-26
— 60.7 mi, about 1h 8m
Turn-by-Turn Driving Directions
Step-by-step road directions between Thermopolis, WY and Casper, WY.
1
Start on US 20; WY 789
0.5 mi
·
1 min
·
South 6th Street
Use the straight / left / right lanes.
2
Turn right onto US 20; WY 789
0.9 mi
·
2 min
·
Shoshoni Street
Use the left / slight right lanes.
3
Continue on US 20; WY 789
31 mi
·
36 min
·
US 20; WY 789
Use the straight / right lanes.
4
Turn left onto US 20; US 26
33 mi
·
37 min
·
East 2nd Street
5
Continue on US 20; US 26
61 mi
·
1 hr 8 min
·
West US Highway 20-26
6
Turn left onto US 20; US 26
2.7 mi
·
3 min
·
US 20; US 26
7
Take the exit
2.5 mi
·
3 min
8
Take the exit onto US 20; US 26; US 87
0.3 mi
·
41 sec
·
US 20; US 26; US 87
Toward US 20 East, US 26 East, US 87 South: North Beverly Street, Bryan Stock Trail
9
At end of road, turn left onto I 25 Business
1.1 mi
·
2 min
·
Bryan Stock Trail
10
Turn left onto East Sunlight Drive
0.9 mi
·
3 min
·
East Sunlight Drive
11
Arrive at destination
North Sunlight Drive
Trip Plan
Given the manageable duration of the trip, you have plenty of flexibility regarding your departure time, though planning for at least one stop is recommended to break up the drive. Keep an eye on your fuel gauge before setting out, as the $21 cost estimate can fluctuate based on local prices along the route. Since you are covering over 130 miles, try to time your transit to avoid peak traffic hours when entering Casper on East 2nd Street. Because this is a highway-heavy route, ensure your vehicle is prepared for consistent speeds over the 60.7-mile stretch of West US Highway 20-26. Taking a quick breather mid-trip will keep you refreshed for the final approach into the city.
Morning Departure
Leave by 9 AM and you'll arrive before lunch.
Evening Departure
Even a 4 PM departure gets you there before dark in summer.
You can normally do this drive in one day.
Plan roughly 1 meaningful break for fuel, food, and rest.
The halfway point lands around 66.9 miles from Thermopolis, WY, or about 1h 19m into the drive.
The longest continuous stretch on this route runs about 60.7 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 80 miles or 1h 34m in
Use this first pause for coffee, a restroom break, and a quick traffic check ahead.
Halfway reset
Around 66.9 miles or 1h 19m 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 7m
Traffic, exits, and arrival timing usually matter more near Casper, WY than in the middle of the route.
Before You Leave
+
Open the route before leaving Thermopolis, WY 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 Thermopolis, WY
This is one driving day of about 133.8 miles and 2h 39m.
Your first comfortable stop window is around 80 miles from Thermopolis, WY.
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 West US Highway 20-26 for about 60.7 miles.
Where to Stop
Rest stops, refuel points, and overnight suggestions along this route.
Halfway Point
Midpoint
About 66.9 mi from Thermopolis, WY · 1h 19m into the drive
Mid-route town
Meal stop
67 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 80 miles helps settle the day before fatigue starts building.
Meal break
The midpoint is around 66.9 miles from Thermopolis, WY, which is a good place for a longer meal and fuel stop.
Before the longest stretch
Fuel checkTop up before West US Highway 20-26 if your tank is already low. That segment runs about 60.7 miles.
Arriving in Casper, WY
The final approach into Casper, WY 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 Casper, WY.
These stop ideas are pacing suggestions — the exact town or exit can change with traffic, hotel plans, and fuel range.
Fuel & Cost
Regular Gas
$21.20 one way
$42.41 round trip
$4.03/gal
25.4 MPG avg
47 kg CO2
| Fuel Type | $/gal | One Way | Round Trip |
|---|---|---|---|
| midgrade | $4.23 | $22.29 | $44.58 |
| premium | $4.53 | $23.86 | $47.71 |
| diesel | $5.64 | $29.73 | $59.45 |
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: 46.8 kg one way. Prices: EIA weekly data, 2026-04-06.
Driving Electric?
About $14 in charging · 0 stops · 66% less CO2
| Vehicle Type | kWh | Stops | DC Fast | Home Charge |
|---|---|---|---|---|
| Average EV | 40.1 | 0 | $14.05 | $6.42 |
| Efficient EV | 33.5 | 0 | $11.71 | $5.35 |
| EV Truck/SUV | 53.5 | 0 | $18.73 | $8.56 |
Gas CO2
47 kg
EV CO2
16 kg (66% 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
Casper, WY
Afternoon in Casper on Sunday
Local time
4:48 PM
MDT
Current temp
39°F
Unavailable
Live forecast
Along the Route
35°F
Riverton, WY
67 mi in
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
12 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
2h 39m 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 Thermopolis, WY to Casper, WY covers 133.8 miles and takes about 2h 39m without stops. Add 15-30 minutes for a fuel or rest stop on longer drives.
The main roads are West US Highway 20-26, US 20, East 2nd Street. Most of the drive stays on highways, so watch for ramps and exits.
This is a comfortable same-day trip.
The midpoint is about 66.9 miles from Thermopolis, WY. Look for rest areas, gas stations, or food options near the halfway mark.
At current regular gas prices, expect to spend about $21.20 one way. This estimate uses 25.4 MPG — your actual cost will vary with your vehicle's fuel efficiency and current gas prices.
Leave by 9 AM and you'll arrive before lunch. Even a 4 PM departure gets you there before dark in summer.
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 2h 39m drive. You will face about 8 decision points, but nothing that requires special attention if you follow navigation.
The main spots that need attention: near the start (US 20; WY 789 / South 6th Street): Lane positioning matters here; at 0.5 miles (US 20; WY 789 / Shoshoni Street): Lane positioning matters here; at 128.9 miles: Exit ramp - move to the correct lane early.
The route from Thermopolis, WY to Casper, WY does not surface many named destination signs beyond the main corridor.
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