How far is Lamar, CO from Thornton, CO?
The driving distance from Lamar, CO to Thornton, CO is about 209.3 miles (336.8 km), with a travel time of about 03h 35m by car.
- The straight-line flight distance is about 176.3 miles (283.7 km).
- For a round trip, plan for roughly 07h 11m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 6:00 AM to 8:00 AM MDT.
Reverse, save, or send this route
This drive is better planned with a longer stop or an overnight stay. Copy the route link, send it to another device, or print a clean version before you head out.
This drive is better planned with a longer stop or an overnight stay.
Flight Distance
Driving Distance
Gas Cost Calculator
Leave and Arrive Planner
Pick a departure time to see your estimated arrival and same-day return window.
Drive time stays fixed at 03h 35m.
An early departure helps you fit a real stop into the day without turning the return into a late-night drive.
You are leaving earlier than the recommended window, which gives you extra margin for breaks and traffic.
Halfway Point
A useful midpoint for breaks, coffee, or meeting in the middle.
Town in Colorado, United States
Route Weather Snapshot
Check the forecast at both ends before you head out.
Sunny
Driving Route Map
The map below follows the saved road route between Lamar and Thornton.
Turn-by-Turn Driving Directions
Step-by-step road directions between Lamar and Thornton.
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1
Start on West Elm Street
133 m · 21 sec · West Elm Street
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2
Turn left onto South Main Street
1.8 mi · 4 min · South Main Street
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3
Continue straight
5.7 mi · 7 min
-
4
Take the exit slight right toward US 287 North: Limon
1885 ft · 32 sec
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5
Keep slight right to continue on US 287 North: Limon
107.6 mi · 2 hr 7 min
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6
Turn left onto I 70 West: Denver
1634 ft · 40 sec
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7
Merge slight left onto Dwight D. Eisenhower Highway
76.6 mi · 1 hr 17 min · Dwight D. Eisenhower Highway
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8
Continue on Tuskegee Airmen Memorial Highway
3.4 mi · 4 min · Tuskegee Airmen Memorial Highway
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9
Keep slight right to continue on Tuskegee Airmen Memorial Highway
2.8 mi · 4 min · Tuskegee Airmen Memorial Highway
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10
Keep slight right to continue on Dwight D. Eisenhower Highway
6.6 mi · 9 min · Dwight D. Eisenhower Highway
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11
Take the exit slight right toward I 25 North: Fort Collins
1690 ft · 41 sec
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12
Merge slight left onto North Valley Highway
1.3 km · 1 min · North Valley Highway
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13
Keep slight right to continue on North Valley Highway
1.3 mi · 2 min · North Valley Highway
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14
Take the exit slight right toward Thornton Parkway
2280 ft · 43 sec
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15
Turn right onto Thornton Parkway
1.4 km · 2 min · Thornton Parkway
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16
Turn right onto Dorothy Boulevard
1077 ft · 51 sec · Dorothy Boulevard
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17
Turn right
36 m · 9 sec
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18
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Lamar and Thornton.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
US 287 North
Keep slight right to continue on US 287 North: Limon
108 mi · 02h 07m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A longer out-and-back drive
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
Sunny leaving Lamar and Sunny near Thornton.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Lamar to Thornton?
The road trip is about 209.3 miles (336.8 km) and usually takes 03h 35m in normal driving conditions.
Is this a same-day trip or an overnight route?
This is still possible in one day, but it becomes a long driving day. Leaving early and planning your stop window matters more here.
What is the halfway point on this route?
Hugo is a useful midpoint, sitting about 104.5 miles from Lamar and 104.8 miles from Thornton.
How much longer is the road route than the straight-line distance?
The direct path is about 176.3 miles (283.7 km), while the road route adds roughly 33 extra miles because roads do not follow the straight air line.
When is the best time to leave for this route?
A good departure window is usually 6:00 AM to 8:00 AM MDT. If you want a more comfortable same-day return, try to leave by 9:48 AM MDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $27.33 one way or $54.66 round trip. Estimated CO2 is about 65.7 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Lamar and Sunny near Thornton.
Flight Path Map
This map shows the direct air route between Lamar and Thornton. Straight-line distance: 176.3 mi (283.73 km).
#1 Lamar
City in Colorado
| Population | 7,641 |
| Coordinates | 38.0872300, -102.6207500 |
| Altitude | 1103 |
| Country | United States |
#2 Thornton
The seventh most populous city in Colorado.
| Population | 148,113 |
| Coordinates | 39.8680400, -104.9719200 |
| Altitude | 1631 |
| Country | United States |
End: (-104.971859, 39.868064)
Estimated Travel Time
Distance: 337 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 06h 58m |
| 40 mph (64.37 km/h) | 05h 13m |
| 50 mph (80.47 km/h) | 04h 11m |
| 60 mph (96.56 km/h) | 03h 29m |
| 70 mph (112.65 km/h) | 02h 59m |
| 80 mph (129 km/h) | 02h 36m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.70 | $27.33 | $54.66 |
| Mid-grade | $4.08 | $30.18 | $60.36 |
| Premium | $4.39 | $32.45 | $64.90 |
| Diesel | $4.74 | $35.01 | $70.01 |
Assumes 8.3 L/100 km (about 28.3 MPG). CO2 is an estimate and varies by vehicle, fuel blend, traffic, and terrain.
Prices in Colorado · Apr 23, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.