How far is Longmont, CO from Castle Rock, CO?
The driving distance from Longmont, CO to Castle Rock, CO is about 79.1 miles (127.3 km), with a travel time of about 01h 15m by car.
- The straight-line flight distance is about 56.5 miles (90.9 km).
- For a round trip, plan for roughly 02h 30m of driving time before adding stops, traffic, or weather delays.
- A comfortable departure window is usually 8:00 AM to 10:00 AM MDT.
Reverse, save, or send this route
This route works well as a day trip with time at the destination. Copy the route link, send it to another device, or print a clean version before you head out.
This route works well as a day trip with time at the destination.
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 01h 15m.
A morning start gives you useful time at the destination and keeps the return out of the late evening.
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.
Census designated place
Route Weather Snapshot
Check the forecast at both ends before you head out.
Partly Sunny then Chance Showers And Thunderstorms
Partly Sunny then Chance Showers And Thunderstorms
Driving Route Map
The map below follows the saved road route between Longmont and Castle Rock.
Turn-by-Turn Driving Directions
Step-by-step road directions between Longmont and Castle Rock.
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1
Start on the route
19 m · 7 sec
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2
Turn right onto 5th Avenue
1025 ft · 47 sec · 5th Avenue
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3
Turn right onto Collyer Street
1255 ft · 42 sec · Collyer Street
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4
Turn left onto 3rd Avenue
1.8 mi · 3 min · 3rd Avenue
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5
Turn left onto East Ken Pratt Boulevard
1.6 mi · 2 min · East Ken Pratt Boulevard
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6
Continue on Highway 119
3 mi · 4 min · Highway 119
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7
Take the exit right toward I 25 South
2690 ft · 1 min · West I 25 Frontage Road
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8
Merge slight left onto Dwight D. Eisenhower Highway
11.9 mi · 12 min · Dwight D. Eisenhower Highway
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9
Continue on North Valley Highway
3187 ft · 36 sec · North Valley Highway
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10
Keep slight right to continue on North Valley Highway
8.8 mi · 11 min · North Valley Highway
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11
Keep slight right to continue on North Valley Highway
36.1 mi · 43 min · North Valley Highway
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12
Take the exit slight right toward Wilcox Street, Wolfensberger Road
1213 ft · 32 sec
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13
Turn left onto East Wolfensberger Road
132 m · 21 sec · East Wolfensberger Road
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14
Continue on North Wilcox Street
2093 ft · 1 min · North Wilcox Street
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15
Turn left onto 5th Street
979 ft · 37 sec · 5th Street
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16
Turn right onto North Cantril Street
837 ft · 29 sec · North Cantril Street
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17
Arrive at your destination
0 m · 1 sec · North Cantril Street
Car Route Details
A richer read on the saved driving route between Longmont and Castle Rock.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
North Valley Highway
Keep slight right to continue on North Valley Highway
36.1 mi · 00h 43m
Route Summary
A quick read on whether this route feels easy, ambitious, or worth planning around.
A comfortable day-trip route
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
Partly Sunny then Chance Showers And Thunderstorms leaving Longmont and Partly Sunny then Chance Showers And Thunderstorms near Castle Rock.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Longmont to Castle Rock?
The road trip is about 79.1 miles (127.3 km) and usually takes 01h 15m in normal driving conditions.
Is this a same-day trip or an overnight route?
This route works well as a day trip. You can leave in the morning, spend meaningful time at the destination, and still return the same day.
What is the halfway point on this route?
Berkley is a useful midpoint, sitting about 33 miles from Longmont and 46.2 miles from Castle Rock.
How much longer is the road route than the straight-line distance?
The direct path is about 56.5 miles (90.9 km), while the road route adds roughly 22.6 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 8:00 AM to 10:00 AM MDT. If you want a more comfortable same-day return, try to leave by 4:00 PM MDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $10.32 one way or $20.63 round trip. Estimated CO2 is about 24.8 kg one way.
What should you check before leaving?
Before you leave, expect Partly Sunny then Chance Showers And Thunderstorms around Longmont and Partly Sunny then Chance Showers And Thunderstorms near Castle Rock.
Stop Ideas Near Berkley
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Fairplay Park
Denver City Council
Town Hall Arts Center
Municipal Court Park
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Berkley.
Union Station
Denver (Bus Station), Colorado
Boulder, Colorado
Longmont, Colorado
Flight Path Map
This map shows the direct air route between Longmont and Castle Rock. Straight-line distance: 56.46 mi (90.86 km).
#1 Longmont
The most populous city in Boulder County, Colorado.
| Population | 98,445 |
| Coordinates | 40.1672100, -105.1019300 |
| Altitude | 1519 |
| Country | United States |
#2 Castle Rock
The most populous city in Douglas County, Colorado.
| Population | 70,567 |
| Coordinates | 39.3722100, -104.8560900 |
| Altitude | 1897 |
| Country | United States |
End: Cantril Street (-104.856315, 39.3722)
Estimated Travel Time
Distance: 127 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 02h 38m |
| 40 mph (64.37 km/h) | 01h 58m |
| 50 mph (80.47 km/h) | 01h 34m |
| 60 mph (96.56 km/h) | 01h 19m |
| 70 mph (112.65 km/h) | 01h 07m |
| 80 mph (129 km/h) | 00h 59m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.70 | $10.32 | $20.63 |
| Mid-grade | $4.08 | $11.39 | $22.79 |
| Premium | $4.39 | $12.25 | $24.50 |
| Diesel | $4.74 | $13.22 | $26.43 |
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 · May 26, 2026
Distance to Other Cities
Planning a road trip? See the full trip guide on Trip.ovh — stops, fuel costs, weather, and departure timing.