How far is Castle Rock, CO from Milliken, CO?
The driving distance from Castle Rock, CO to Milliken, CO is about 77.7 miles (125.1 km), with a travel time of about 01h 34m by car.
- The straight-line flight distance is about 66.1 miles (106.4 km).
- For a round trip, plan for roughly 03h 09m 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 34m.
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.
The seventh most populous city in Colorado.
Route Weather Snapshot
Check the forecast at both ends before you head out.
Sunny
Mostly Sunny
Driving Route Map
The map below follows the saved road route between Castle Rock and Milliken.
Turn-by-Turn Driving Directions
Step-by-step road directions between Castle Rock and Milliken.
-
1
Start on North Cantril Street
27 m · 8 sec · North Cantril Street
-
2
Turn left onto 3rd Street
641 ft · 23 sec · 3rd Street
-
3
Exit the roundabout onto 3rd Street
135 m · 18 sec · 3rd Street
-
4
Turn right onto North Wilcox Street
2807 ft · 2 min · North Wilcox Street
-
5
Take the ramp straight toward I 25 North
1715 ft · 42 sec
-
6
Merge slight left
35.9 mi · 43 min
-
7
Keep slight right to continue on North Valley Highway
4.3 mi · 6 min · North Valley Highway
-
8
Keep slight right to continue on North Valley Highway
5.3 mi · 6 min · North Valley Highway
-
9
Continue on Dwight D. Eisenhower Highway
24.2 mi · 24 min · Dwight D. Eisenhower Highway
-
10
Take the exit slight right toward CO 60 East: Johnstown, Milliken
1697 ft · 41 sec
-
11
Keep slight right
84 m · 7 sec
-
12
Turn straight onto West South 1st Street
6.5 mi · 11 min · West South 1st Street
-
13
Turn right onto South Grace Avenue
46 m · 14 sec · South Grace Avenue
-
14
Turn left
52 m · 15 sec
-
15
Turn right
33 m · 8 sec
-
16
Arrive at your destination
0 m · 1 sec
Car Route Details
A richer read on the saved driving route between Castle Rock and Milliken.
Highway-focused drive
Most of the mileage stays on named highways, so the important moments are ramps, exits, merges, and the final local approach.
I 25 North
Merge slight left
35.9 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.
Sunny leaving Castle Rock and Mostly Sunny near Milliken.
Trip Questions
Direct answers travelers usually want before committing to the drive.
How long does it take to drive from Castle Rock to Milliken?
The road trip is about 77.7 miles (125.1 km) and usually takes 01h 34m 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?
Thornton is a useful midpoint, sitting about 38.9 miles from Castle Rock and 38.8 miles from Milliken.
How much longer is the road route than the straight-line distance?
The direct path is about 66.1 miles (106.4 km), while the road route adds roughly 11.6 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 3:20 PM MDT.
How much will gas cost for this route?
Using about 28.3 MPG, regular gas is estimated at $10.13 one way or $20.27 round trip. Estimated CO2 is about 24.4 kg one way.
What should you check before leaving?
Before you leave, expect Sunny around Castle Rock and Mostly Sunny near Milliken.
Stop Ideas Near Thornton
Useful break, food, and waypoint ideas within about 15 miles of the route midpoint.
Fairplay Park
Denver City Council
Lafayette City Hall
Municipal Court Park
Transit and Meeting Points
Useful pickup, handoff, or rendezvous points close to Thornton.
Denver (Bus Station), Colorado
Union Station
Boulder, Colorado
Longmont, Colorado
Flight Path Map
This map shows the direct air route between Castle Rock and Milliken. Straight-line distance: 66.14 mi (106.44 km).
#1 Castle Rock
The most populous city in Douglas County, Colorado.
| Population | 70,567 |
| Coordinates | 39.3722100, -104.8560900 |
| Altitude | 1897 |
| Country | United States |
#2 Milliken
City in Weld County, Colorado, United States of America
| Population | 8,688 |
| Coordinates | 40.3294300, -104.8552500 |
| Altitude | 1448 |
| Country | United States |
End: Milliken (-104.85525, 40.32943)
Estimated Travel Time
Distance: 125 km by road
| Speed | Time |
|---|---|
| 30 mph (48.3 km/h) | 02h 35m |
| 40 mph (64.37 km/h) | 01h 56m |
| 50 mph (80.47 km/h) | 01h 33m |
| 60 mph (96.56 km/h) | 01h 17m |
| 70 mph (112.65 km/h) | 01h 06m |
| 80 mph (129 km/h) | 00h 58m |
Fuel, Round Trip and CO2
Estimated fuel cost and emissions for this route.
| Fuel | $/gal | One way | Round trip |
|---|---|---|---|
| Regular gas | $3.70 | $10.13 | $20.27 |
| Mid-grade | $4.08 | $11.19 | $22.38 |
| Premium | $4.39 | $12.03 | $24.06 |
| Diesel | $4.74 | $12.98 | $25.96 |
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.